Extended Lojban Grammar (a draft)

From Lojban
Jump to navigation Jump to search
Independent reference grammar of Lojban.

Lojban (pronounced as [ˈloʒban]) is a new cool language.

It is a constructed language based on so called predicate logic which makes it kind of a bridge between different languages and cultures.

Lojban, the Odyssey to our Universe.

What is unique about this language? All natural grown languages have inner drawbacks like complications in grammar rules, biases and restrictions that discourage other ways of thinking.

Lojban is designed to free us from these restrictions and see the world brighter.

Here are its advantages:

  • Lojban speech allows you to say things shorter without unnecessary distracting details. For example, you don't have to always think of what tense (past, present or future) to use in a verb when it's already clear from context. When you need details you add them. But unlike other languages Lojban doesn't force you to do so.
  • Lojban has unprecedented tools for expressing human emotions.
  • Lojban is made consistent and easy to extend. There are no exclusions in grammar. There are nice ways of extending existing vocabulary.

Ask a question on Lojban on the guest board

Lojban is an endless journey

Being carefully worked-out in design by its creators this language accurately and precisely reveals the delicate aspects of logic and our mentality.

  • Lojban is clean, simple, and with all these advantages powerful language. Why not start speaking it?
  • Lojban is for artists that would adore expressing tiny details of human emotions
  • Lojban is for lovers of wisdom (philosophers, in the original sense)
  • Lojban is for scientists that like all concepts to be put in a concise system.
  • Lojban is the best tool for implementing machine automatic translation. Still it's a speakable language.
  • Lojban breaks the barrier of misunderstanding of people with different background.
  • Lastly, Lojban is also fun !

Lojban is easy to learn - the number of root words is only 1341. Not that much to learn to start speaking!

Alphabet and phonology

Lojban is designed so that any properly spoken Lojban utterance can be uniquely transcribed in writing, and any properly written Lojban can be spoken so as to be uniquely reproduced by another person. As a consequence, the standard Lojban orthography must assign to each distinct sound, or phoneme, a unique letter or symbol. Each letter or symbol has only one sound or, more accurately, a limited range of sounds that are permitted pronunciations for that phoneme. Some symbols indicate stress (speech emphasis) and pause, which are also essential to Lojban word recognition. In addition, everything that is represented in other languages by punctuation (when written) or by tone of voice (when spoken) is represented in Lojban by words. These two properties together are known technically as “audio-visual isomorphism”.

Lojban uses a variant of the Latin (Roman) alphabet, consisting of the following letters and symbols:

, . ` a b c d e f g i j k l m n o p r s t u v x y z omitting the letters “h”, “q”, and “w”.

The alphabetic order given above is that of the ASCII coded character set, widely used in computers. By making Lojban alphabetical order the same as ASCII, computerized sorting and searching of Lojban text is facilitated.

Capital letters are used only to represent non-standard stress, which can appear only in the representation of Lojbanized names. Thus the English name “Josephine”, as normally pronounced, is Lojbanized as DJOsefin., pronounced ['dʒosɛfinʔ]. Technically, it is sufficient to capitalize the vowel letter, in this case O, but it is easier on the reader to capitalize the whole syllable.

Another method of dealing with stress is to put the letter ` immediately before the stressed phoneme.

Without the capitalization, the ordinary rules of Lojban stress would cause the se syllable to be stressed. Lojbanized names are meant to represent the pronunciation of names from other languages with as little distortion as may be; as such, they are exempt from many of the regular rules of Lojban phonology, as will appear in the rest of this chapter.

Basic Phonetics

Lojban pronunciations are defined using the International Phonetic Alphabet, or IPA, a standard method of transcribing pronunciations. By convention, IPA transcriptions are always within square brackets: for example, the word “cat” is pronounced (in General American pronunciation) [kæt]. Section 2.6 contains a brief explanation of the IPA characters used in this chapter, with their nearest analogues in English, and will be especially useful to those not familiar with the technical terms used in describing speech sounds.

The standard pronunciations and permitted variants of the Lojban letters are listed in the table below. The descriptions have deliberately been made a bit ambiguous to cover variations in pronunciation by speakers of different native languages and dialects. In all cases except r the first IPA symbol shown represents the preferred pronunciation; for r, all of the variations (and any other rhotic sound) are equally acceptable. <tab class=wikitable> Letter IPA X-SAMPA Description ' [h] [h] an unvoiced glottal spirant , - - the syllable separator . [ʔ] [?] a glottal stop or a pause a [a], [ɑ] [a], [A] an open vowel b [b] [b] a voiced bilabial stop c [ʃ], [ʂ] [S], [s`] an unvoiced coronal sibilant d [d] [d] a voiced dental/alveolar stop e [ɛ], [e] [E], [e] a front mid vowel f [f], [ɸ] [f], [p\] an unvoiced labial fricative g [ɡ] [g] a voiced velar stop i [i] [i] a front close vowel j [ʒ], [ʐ] [Z], [z`] a voiced coronal sibilant k [k] [k] an unvoiced velar stop l [l], [l̩] [l], [l=] a voiced lateral approximant (may be syllabic) m [m], [m̩] [m], [m=] a voiced bilabial nasal (may be syllabic) n [n], [n̩], [ŋ], [ŋ̍] [n], [n=], [N], [N=] a voiced dental or velar nasal (may be syllabic) o [o], [ɔ] [o], [O] a back mid vowel p [p] [p] an unvoiced bilabial stop r [r], [ɹ], [ɾ], [ʀ], [r̩], [ɹ̩], [ɾ̩], [ʀ̩] [r], [r\], [4], [R\], [r=], [r\=], [4=], [R\=] a rhotic sound s [s] [s] an unvoiced alveolar sibilant t [t] [t] an unvoiced dental/alveolar stop u [u] [u] a back close vowel v [v], [β] [v], [B] a voiced labial fricative x [x] [x] an unvoiced velar fricative y [ə] [@] a central mid vowel z [z] [z] a voiced alveolar sibilant </tab> The Lojban sounds must be clearly pronounced so that they are not mistaken for each other. Voicing and placement of the tongue are the key factors in correct pronunciation, but other subtle differences will develop between consonants in a Lojban-speaking community. At this point these are the only mandatory rules on the range of sounds.

Note in particular that Lojban vowels can be pronounced with either rounded or unrounded lips; typically o and u are rounded and the others are not, as in English, but this is not a requirement; some people round y as well. Lojban consonants can be aspirated or unaspirated. Palatalizing of consonants, as found in Russian and other languages, is not generally acceptable in pronunciation, though a following i may cause it.

The sounds represented by the letters c, g, j, s, and x require special attention for speakers of English, either because they are ambiguous in the orthography of English (c, g, s), or because they are strikingly different in Lojban (c, j, x). The English “c” represents three different sounds, [k] in “cat” and

[s] in “cent”, as well as the [ʃ] of “ocean”. Similarly, English “g” can represent [ɡ] as in “go”, [dʒ] as in “gentle”, and [ʒ] as in the second "g" in “garage” (in some pronunciations). English “s” can be either [s] as in “cats”, [z] as in “cards”, [ʃ] as in “tension”, or [ʒ] as in “measure”. The sound of Lojban x doesn't appear in most English dialects at all.

There are two common English sounds that are found in Lojban but are not Lojban consonants: the “ch” of “church” and the “j” of “judge”. In Lojban, these are considered two consonant sounds spoken together without an intervening vowel sound, and so are represented in Lojban by the two separate consonants: tc (IPA [tʃ]) and dj (IPA [dʒ]). In general, whether a complex sound is considered one sound or two depends on the language: Russian views “ts” as a single sound, whereas English, French, and Lojban consider it to be a consonant cluster.

The Special Lojban Characters

The apostrophe, period, and comma need special attention. They are all used as indicators of a division between syllables, but each has a different pronunciation, and each is used for different reasons:

The apostrophe represents a phoneme similar to a short, breathy English “h”, (IPA [h]). The letter “h” is not used to represent this sound for two reasons: primarily in order to simplify explanations of the morphology, but also because the sound is very common, and the apostrophe is a visually lightweight representation of it. The apostrophe sound is a consonant in nature, but is not treated as either a consonant or a vowel for purposes of Lojban morphology (word-formation), which is explained in Chapter 5. In addition, the apostrophe visually parallels the comma and the period, which are also used (in different ways) to separate syllables.

The apostrophe is included in Lojban only to enable a smooth transition between vowels, while joining the vowels within a single word. In fact, one way to think of the apostrophe is as representing an unvoiced vowel glide.

As a permitted variant, any unvoiced fricative other than those already used in Lojban may be used to render the apostrophe: IPA [θ] is one possibility. The convenience of the listener should be regarded as paramount in deciding to use a substitute for [h].

The period represents a mandatory pause, with no specified length; a glottal stop (IPA

[ʔ]) is considered a pause of shortest length. A pause (or glottal stop) may appear between any two words, and in certain cases – explained in detail in

Section 5.8 – must occur. In particular, a word beginning with a vowel is always preceded by a pause, and a word ending in a consonant is always followed by a pause.

Technically, the period is an optional reminder to the reader of a mandatory pause that is dictated by the rules of the language; because these rules are unambiguous, a missing period can be inferred from otherwise correct text. Periods are included only as an aid to the reader.

A period also may be found apparently embedded in a word. When this occurs, such a written string is not one word but two, written together to indicate that the writer intends a unitary meaning for the compound. It is not really necessary to use a space between words if a period appears.

The comma is used to indicate a syllable break within a word, generally one that is not obvious to the reader. Such a comma is written to separate syllables, but indicates that there must be no pause between them, in contrast to the period. Between two vowels, a comma indicates that some type of glide may be necessary to avoid a pause that would split the two syllables into separate words. It is always legal to use the apostrophe (IPA

[h]) sound in pronouncing a comma. However, a comma cannot be pronounced as a pause or glottal stop between the two letters separated by the comma, because that pronunciation would split the word into two words.

Otherwise, a comma is usually only used to clarify the presence of syllabic l, m, n, or r (discussed later). Commas are never required: no two Lojban words differ solely because of the presence or placement of a comma.

Here is a somewhat artificial example of the difference in pronunciation between periods, commas and apostrophes. In the English song about Old MacDonald's Farm, the vowel string which is written as “ee-i-ee-i-o” in English could be Lojbanized with periods as:

Example 2.1:
[ʔi ʔaj ʔi ʔaj ʔo]
Ee! Eye! Ee! Eye! Oh!

However, this would sound clipped, staccato, and unmusical compared to the English. Furthermore, although Example 2.1 is a string of meaningful Lojban words, as a sentence it makes very little sense. (Note the use of periods embedded within the written word.)

If commas were used instead of periods, we could represent the English string as a Lojbanized name, ending in a consonant:

Example 2.2:
[ʔi jaj ji jaj jonʔ]

The commas represent new syllable breaks, but prohibit the use of pauses or glottal stop. The pronunciation shown is just one possibility, but closely parallels the intended English pronunciation.

However, the use of commas in this way is risky to unambiguous interpretation, since the glides might be heard by some listeners as diphthongs, producing something like

Example 2.3:

which is technically a different Lojban name. Since the intent with Lojbanized names is to allow them to be pronounced more like their native counterparts, the comma is allowed to represent vowel glides or some non-Lojbanic sound. Such an exception affects only spelling accuracy and the ability of a reader to replicate the desired pronunciation exactly; it will not affect the recognition of word boundaries.

Still, it is better if Lojbanized names are always distinct. Therefore, the apostrophe is preferred in regular Lojbanized names that are not attempting to simulate a non-Lojban pronunciation perfectly. (Perfection, in any event, is not really achievable, because some sounds simply lack reasonable Lojbanic counterparts.)

If apostrophes were used instead of commas in Example 2.2, it would appear as:

Example 2.4:
[ʔi hai hi hai honʔ]

which preserves the rhythm and length, if not the exact sounds, of the original English.

Diphthongs and Syllabic Consonants

There exist 16 diphthongs in the Lojban language. A diphthong is a vowel sound that consists of two elements, a short vowel sound and a glide, either a labial (IPA [w]) or palatal (IPA [j]) glide, that either precedes (an on-glide) or follows (an off-glide) the main vowel. Diphthongs always constitute a single syllable.

For Lojban purposes, a vowel sound is a relatively long speech-sound that forms the nucleus of a syllable. Consonant sounds are relatively brief and normally require an accompanying vowel sound in order to be audible. Consonants may occur at the beginning or end of a syllable, around the vowel, and there may be several consonants in a cluster in either position. Each separate vowel sound constitutes a distinct syllable; consonant sounds do not affect the determination of syllables.

The six Lojban vowels are a, e, i, o, u, and y. The first five vowels appear freely in all kinds of Lojban words. The vowel y has a limited distribution: it appears only in Lojbanized names, in the Lojban names of the letters of the alphabet, as a glue vowel in compound words, and standing alone as a space-filler word (like English “uh” or “er”).

The Lojban diphthongs are shown in the table below. (Variant pronunciations have been omitted, but are much as one would expect based on the variant pronunciations of the separate vowel letters: ai may be pronounced

[ɑj], for example.)

<tab class=wikitable head=top> Letters IPA Description ai [aj] an open vowel with palatal off-glideei [ɛj] a front mid vowel with palatal off-glideoi [oj] a back mid vowel with palatal off-glideau [aw] an open vowel with labial off-glideia [ja] an open vowel with palatal on-glideie [jɛ] a front mid vowel with palatal on-glideii [ji] a front close vowel with palatal on-glideio [jo] a back mid vowel with palatal on-glideiu [ju] a back close vowel with palatal on-glideua [wa] an open vowel with labial on-glideue [wɛ] a front mid vowel with labial on-glideui [wi] a front close vowel with labial on-glideuo [wo] a back mid vowel with labial on-glideuu [wu] a back close vowel with labial on-glideiy [jə] a central mid vowel with palatal on-glideuy [wə] a central mid vowel with labial on-glide

(Approximate English equivalents of most of these diphthongs exist: See Section for examples.)

The first four diphthongs above ( ai, ei, oi, and au, the ones with off-glides) are freely used in most types of Lojban words; the ten following ones are used only as stand-alone words and in Lojbanized names and borrowings; and the last two ( iy and uy) are used only in Lojbanized names.

The syllabic consonants of Lojban, [l̩], [m̩], [n̩], and [r̩], are variants of the non-syllabic [l], [m], [n], and [r] respectively. They normally have only a limited distribution, appearing in Lojban names and borrowings, although in principle any l, m, n, or r may be pronounced syllabically. If a syllabic consonant appears next to a l, m, n, or r that is not syllabic, it may not be clear which is which:


is a hypothetical Lojbanized name with more than one valid pronunciation; however it is pronounced, it remains the same word.

Syllabic consonants are treated as consonants rather than vowels from the standpoint of Lojban morphology. Thus Lojbanized names, which are generally required to end in a consonant, are allowed to end with a syllabic consonant. An example is rl., which is an approximation of the English name “Earl”, and has two syllabic consonants.

Syllables with syllabic consonants and no vowel are never stressed or counted when determining which syllables to stress (see Section 2.5).

Vowel Pairs

Lojban vowels also occur in pairs, where each vowel sound is in a separate syllable. These two vowel sounds are connected (and separated) by an apostrophe. Lojban vowel pairs should be pronounced continuously with the [h] sound between (and not by a glottal stop or pause, which would split the two vowels into separate words).

All vowel combinations are permitted in two-syllable pairs with the apostrophe separating them; this includes those which constitute diphthongs when the apostrophe is not included.

The Lojban vowel pairs are: a'a, a'e, a'i, a'o, a'u, a'y, e'a, e'e, e'i, e'o, e'u, e'y, i'a, i'e, i'i, i'o, i'u, i'y, o'a, o'e, o'i, o'o, o'u, o'y, u'a, u'e, u'i, u'o, u'u, u'y, y'a, y'e, y'i, y'o, y'u, y'y.

Vowel pairs involving y appear only in Lojbanized names. They could appear in cmavo (structure words), but only .y'y. is so used – it is the Lojban name of the apostrophe letter (See Section 18.1).

When more than two vowels occur together in Lojban, the normal pronunciation pairs vowels from the left into syllables, as in the Lojbanized name:


Example contains the diphthong ei followed by the vowel i. In order to indicate a different grouping, the comma must always be used, leading to:


which contains the vowel e followed by the diphthong ii. In rough English representation, Example is “May Een”, whereas Example is “Meh Yeen”.

Consonant Clusters

A consonant sound is a relatively brief speech-sound that precedes or follows a vowel sound in a syllable; its presence either preceding or following does not add to the count of syllables, nor is a consonant required in either position for any syllable. Lojban has seventeen consonants: for the purposes of this section, the apostrophe is not counted as a consonant.

An important distinction dividing Lojban consonants is that of voicing. The following table shows the unvoiced consonants and the corresponding voiced ones: <tab class=wikitable> Unvoiced Voiced p b t d k g f v c j s z x - </tab> The consonant x has no voiced counterpart in Lojban. The remaining consonants, l, m, n, and r, are typically pronounced with voice, but can be pronounced unvoiced.

Consonant sounds occur in languages as single consonants, or as doubled, or as clustered combinations. Single consonant sounds are isolated by word boundaries or by intervening vowel sounds from other consonant sounds. Doubled consonant sounds are either lengthened like [s] in English “hiss”, or repeated like [k] in English “backcourt”. Consonant clusters consist of two or more single or doubled consonant sounds in a group, each of which is different from its immediate neighbor. In Lojban, doubled consonants are excluded altogether, and clusters are limited to two or three members, except in Lojbanized names.

Consonants can occur in three positions in words: initial (at the beginning), medial (in the middle), and final (at the end). In many languages, the sound of a consonant varies depending upon its position in the word. In Lojban, as much as possible, the sound of a consonant is unrelated to its position. In particular, the common American English trait of changing a “t” between vowels into a “d” or even an alveolar tap (IPA [ɾ]) is unacceptable in Lojban.

Lojban imposes no restrictions on the appearance of single consonants in any valid consonant position; however, no consonant (including syllabic consonants) occurs final in a word except in Lojbanized names.

Pairs of consonants can also appear freely, with the following restrictions:

  • It is forbidden for both consonants to be the same, as this would violate the rule against double consonants.
  • It is forbidden for one consonant to be voiced and the other unvoiced. The consonants l, m, n, and r are exempt from this restriction. As a result, bf is forbidden, and so is sd, but both fl and vl, and both ls and lz, are permitted.
  • It is forbidden for both consonants to be drawn from the set c, j, s, z.
  • The specific pairs cx, kx, xc, xk, and mz are forbidden.

These rules apply to all kinds of words, even Lojbanized names. If a name would normally contain a forbidden consonant pair, a y can be inserted to break up the pair:

[dʒɛj məzʔ]

The regular English pronunciation of “James”, which is [dʒɛjmz], would Lojbanize as djeimz., which contains a forbidden consonant pair.

Initial Consonant Pairs

The set of consonant pairs that may appear at the beginning of a word (excluding Lojbanized names) is far more restricted than the fairly large group of permissible consonant pairs described in Section 2.3. Even so, it is more than English allows, although hopefully not more than English-speakers (and others) can learn to pronounce.

There are just 48 such permissible initial consonant pairs, as follows: bl br cf ck cl cm cn cp cr ct dj dr dz fl fr gl gr jb jd jg jm jv kl kr ml mr pl pr sf sk sl sm sn sp sr st tc tr ts vl vr xl xr zb zd zg zm zv Lest this list seem almost random, a pairing of voiced and unvoiced equivalent vowels will show significant patterns which may help in learning: pl pr fl fr bl br vl vr

cp cf ct ck cm cn cl cr jb jv jd jg jm sp sf st sk sm sn sl sr zb zv zd zg zm

tc tr ts kl kr dj dr dz gl gr

ml mr xl xr Note that if both consonants of an initial pair are voiced, the unvoiced equivalent is also permissible, and the voiced pair can be pronounced simply by voicing the unvoiced pair. (The converse is not true: cn is a permissible initial pair, but jn is not.)

Consonant triples can occur medially in Lojban words. They are subject to the following rules:

  • The first two consonants must constitute a permissible consonant pair;
  • The last two consonants must constitute a permissible initial consonant pair;
  • The triples ndj, ndz, ntc, and nts are forbidden.

Lojbanized names can begin or end with any permissible consonant pair, not just the 48 initial consonant pairs listed above, and can have consonant triples in any location, as long as the pairs making up those triples are permissible. In addition, names can contain consonant clusters with more than three consonants, again requiring that each pair within the cluster is valid.

Buffering Of Consonant Clusters

Many languages do not have consonant clusters at all, and even those languages that do have them often allow only a subset of the full Lojban set. As a result, the Lojban design allows the use of a buffer sound between consonant combinations which a speaker finds unpronounceable. This sound may be any non-Lojbanic vowel which is clearly separable by the listener from the Lojban vowels. Some possibilities are IPA [ɪ], [ɨ], [ʊ], or even [ʏ], but there probably is no universally acceptable buffer sound. When using a consonant buffer, the sound should be made as short as possible. Two examples showing such buffering (we will use [ɪ] in this chapter) are:

[ˈvru si] or [vɪ ˈru si]
[ʔam ster damʔ] or [ˈʔa mɪ sɪ tɛ rɪ da mɪʔ]

When a buffer vowel is used, it splits each buffered consonant into its own syllable. However, the buffering syllables are never stressed, and are not counted in determining stress. They are, in effect, not really syllables to a Lojban listener, and thus their impact is ignored.

Here are more examples of unbuffered and buffered pronunciations:

[ˈkla ma]
[kɪ ˈla ma]
[ˈxap ʃkɛ]
[ˈxa pɪ ʃkɛ]
[ˈxa pɪ ʃɪ kɛ]

In Example , we see that buffering vowels can be used in just some, rather than all, of the possible places: the second pronunciation buffers the pc consonant pair but not the ck. The third pronunciation buffers both.

[po nə 'ni hu]

Example cannot contain any buffering vowel. It is important not to confuse the vowel y, which is pronounced [ə], with the buffer, which has a variety of possible pronunciations and is never written. Consider the contrast between

[boŋ gə ˈnan ba]

an unlikely Lojban compound word meaning “bone bread” (note the use of [ŋ] as a representative of n before g) and

[boŋ ˈgnan ba]

a possible borrowing from another language (Lojban borrowings can only take a limited form). If Example were pronounced with buffering, as

[boŋ gɪ ˈnan ba]

it would be very similar to Example . Only a clear distinction between y and any buffering vowel would keep the two words distinct.

Since buffering is done for the benefit of the speaker in order to aid pronounceability, there is no guarantee that the listener will not mistake a buffer vowel for one of the six regular Lojban vowels. The buffer vowel should be as laxly pronounced as possible, as central as possible, and as short as possible. Furthermore, it is worthwhile for speakers who use buffers to pronounce their regular vowels a bit longer than usual, to avoid confusion with buffer vowels. The speakers of many languages will have trouble correctly hearing any of the suggested buffer vowels otherwise. By this guideline, Example would be pronounced

[boːŋ gɪ ˈnaːn baː]

with lengthened vowels.

Syllabication And Stress

A Lojban word has one syllable for each of its vowels, diphthongs, and syllabic consonants (referred to simply as “vowels” for the purposes of this section.) Syllabication rules determine which of the consonants separating two vowels belong to the preceding vowel and which to the following vowel. These rules are conventional only; the phonetic facts of the matter about how utterances are syllabified in any language are always very complex.

A single consonant always belongs to the following vowel. A consonant pair is normally divided between the two vowels; however, if the pair constitute a valid initial consonant pair, they are normally both assigned to the following vowel. A consonant triple is divided between the first and second consonants. Apostrophes and commas, of course, also represent syllable breaks. Syllabic consonants usually appear alone in their syllables.

It is permissible to vary from these rules in Lojbanized names. For example, there are no definitive rules for the syllabication of names with consonant clusters longer than three consonants. The comma is used to indicate variant syllabication or to explicitly mark normal syllabication.

Here are some examples of Lojban syllabication:


This word has no consonant pairs and is therefore syllabified before each medial consonant.


This word is split at a consonant pair.


This word is split at a consonant triple, between the first two consonants of the triple.


This word contains the consonant pair rg; the r may be pronounced syllabically or not.


This word contains the permissible initial pair zb, and so may be syllabicated either between z and b or before zb.

Stress is a relatively louder pronunciation of one syllable in a word or group of words. Since every syllable has a vowel sound (or diphthong or syllabic consonant) as its nucleus, and the stress is on the vowel sound itself, the terms “stressed syllable” and “stressed vowel” are largely interchangeable concepts.

Most Lojban words are stressed on the next-to-the-last, or penultimate, syllable. In counting syllables, however, syllables whose vowel is y or which contain a syllabic consonant ( l, m, n, or r) are never counted. (The Lojban term for penultimate stress is

da'amoi terbasna.) Similarly, syllables created solely by adding a buffer vowel, such as
[ɪ], are not counted.

There are actually three levels of stress – primary, secondary, and weak. Weak stress is the lowest level, so it really means no stress at all. Weak stress is required for syllables containing y, a syllabic consonant, or a buffer vowel.

Primary stress is required on the penultimate syllable of Lojban content words (called brivla). Lojbanized names may be stressed on any syllable, but if a syllable other than the penultimate is stressed, the syllable (or at least its vowel) must be capitalized in writing. Lojban structural words (called cmavo) may be stressed on any syllable or none at all. However, primary stress may not be used in a syllable just preceding a brivla, unless a pause divides them; otherwise, the two words may run together.

Secondary stress is the optional and non-distinctive emphasis used for other syllables besides those required to have either weak or primary stress. There are few rules governing secondary stress, which typically will follow a speaker's native language habits or preferences. Secondary stress can be used for contrast, or for emphasis of a point. Secondary stress can be emphasized at any level up to primary stress, although the speaker must not allow a false primary stress in brivla, since errors in word resolution could result.

The following are Lojban words with stress explicitly shown:


(In a fully-buffered dialect, the pronunciation would be:

['di kə ʒɪ vo].) Note that the syllable ky is not counted in determining stress. The vowel y is never stressed in a normal Lojban context.

This is a Lojbanized version of the name “Armstrong”. The final g must be explicitly pronounced. With full buffering, the name would be pronounced:

[ˈʔa rɪ mɪ sɪ tɪ ro nɪ gɪʔ]

However, there is no need to insert a buffer in every possible place just because it is inserted in one place: partial buffering is also acceptable. In every case, however, the stress remains in the same place: on the first syllable.

The English pronunciation of “Armstrong”, as spelled in English, is not correct by Lojban standards; the letters “ng” in English represent a velar nasal (IPA

[ŋ]) which is a single consonant. In Lojban,

ng represents two separate consonants that must both be pronounced; you may not use

[ŋ] to pronounce Lojban

ng, although

[ŋg] is acceptable. English speakers are likely to have to pronounce the ending with a buffer, as one of the following:
[ˈʔarm stron gɪʔ]


[ˈʔarm stroŋ gɪʔ]

or even

[ˈʔarm stro nɪgʔ]

The normal English pronunciation of the name “Armstrong” could be Lojbanized as:


since Lojban n is allowed to be pronounced as the velar nasal


Here is another example showing the use of y:


This word is a compound word, or lujvo, built from the two affixes bis and dja. When they are joined, an impermissible consonant pair results: sd. In accordance with the algorithm for making lujvo, explained in Section 5.10, a y is inserted to separate the impermissible consonant pair; the y is not counted as a syllable for purposes of stress determination.


These two syllabications sound the same to a Lojban listener – the association of unbuffered consonants in syllables is of no import in recognizing the word.

e'u bridi
e'u BRI,di
E'u BRI,di

In Example , e'u is a cmavo and bridi is a brivla. Either of the first two pronunciations is permitted: no primary stress on either syllable of e'u, or primary stress on the first syllable. The third pronunciation, which places primary stress on the second syllable of the cmavo, requires that – since the following word is a brivla – the two words must be separated by a pause. Consider the following two cases:

le re nobli prenu
le re NObli PREnu
le re no bliprenu
le re no bliPREnu

If the cmavo no in Example were to be stressed, the phrase would sound exactly like the given pronunciation of Example , which is unacceptable in Lojban: a single pronunciation cannot represent both.

IPA For English Speakers

There are many dialects of English, thus making it difficult to define the standardized symbols of the IPA in terms useful to every reader. All the symbols used in this chapter are repeated here, in more or less alphabetical order, with examples drawn from General American. In addition, some attention is given to the Received Pronunciation of (British) English. These two dialects are referred to as GA and RP respectively. Speakers of other dialects should consult a book on phonetics or their local television sets.

  • An IPA indicator of primary stress; the syllable which follows [ˈ] receives primary stress.
  • An allowed variant of Lojban .. This sound is not usually considered part of English. It is the catch in your throat that sometimes occurs prior to the beginning of a word (and sometimes a syllable) which starts with a vowel. In some dialects, like Cockney and some kinds of American English, it is used between vowels instead of “t”: “bottle” [boʔl̩]. The English interjection “uh-oh!” almost always has it between the syllables.
  • A symbol indicating that the previous vowel is to be spoken for a longer time than usual. Lojban vowels can be pronounced long in order to make a greater contrast with buffer vowels.
  • The preferred pronunciation of Lojban a. This sound doesn't occur in GA, but sounds somewhat like the “ar” of “park”, as spoken in RP or New England American. It is pronounced further forward in the mouth than [ɑ].
  • An allowed variant of Lojban a. The “a” of GA “father”. The sound [a] is preferred because GA speakers often relax an unstressed [ɑ] into a schwa [ə], as in the usual pronunciations of “about” and “sofa”. Because schwa is a distinct vowel in Lojban, English speakers must either learn to avoid this shift or to use [a] instead: the Lojban word for “sofa” is sfofa, pronounced :[sfofa] or [sfofɑ] but never [sfofə] which would be the non-word sfofy.
  • Not a Lojban sound. The “a” of English “cat”.
  • The preferred pronunciation of Lojban b. As in English “boy”, “sober”, or “job”.
  • An allowed variant of Lojban v. Not an English sound; the Spanish "b" or "v" between vowels. This sound should not be used for Lojban b.
  • The preferred pronunciation of Lojban d. As in English “dog”, “soda”, or “mad”.
  • The preferred pronunciation of Lojban e. The “e” of English “met”.
  • An allowed variant of Lojban e. This sound is not found in English, but is the Spanish "e", or the tense "e" of Italian. The vowel of English “say” is similar except for the off-glide: you can learn to make this sound by holding your tongue steady while saying the first part of the English vowel.
  • The preferred pronunciation of Lojban y. As in the “a” of English “sofa” or “about”. Schwa is generally unstressed in Lojban, as it is in English. It is a totally relaxed sound made with the tongue in the middle of the mouth.
  • The preferred pronunciation of Lojban f. As in “fee”, “loafer”, or “chef”.
  • An allowed variant of Lojban f. Not an English sound; the Japanese “f” sound.
  • The preferred pronunciation of Lojban g. As in English “go”, “eagle”, or “dog”.
  • The preferred pronunciation of the Lojban apostrophe sound. As in English “aha” or the second "h" in “oh, hello”.
  • The preferred pronunciation of Lojban i. Essentially like the English vowel of “pizza” or “machine”, although the English vowel is sometimes pronounced with an off-glide, which should not be present in Lojban.
  • A possible Lojban buffer vowel. The “i” of English “bit”.
  • A possible Lojban buffer vowel. The “u” of “just” in some varieties of GA, those which make the word sound more or less like “jist”. Also Russian "y" as in "byt'" (to be); like a schwa :[ə], but higher in the mouth.
  • Used in Lojban diphthongs beginning or ending with i. Like the “y” in English “yard” or “say”.
  • The preferred pronunciation of Lojban k. As in English “kill”, “token”, or “flak”.
  • The preferred pronunciation of Lojban l. As in English “low”, “nylon”, or “excel”.
  • The syllabic version of Lojban l, as in English “bottle” or “middle”.
  • The preferred pronunciation of Lojban m. As in English “me”, “humor”, or “ham”.
  • The syllabic version of Lojban m. As in English “catch 'em” or “bottom”.
  • The preferred pronunciation of Lojban n. As in English no, “honor”, or “son”.
  • The syllabic version of Lojban n. As in English “button”.
  • An allowed variant of Lojban n, especially in Lojbanized names and before g or k. As in English “sing” or “singer” (but not “finger” or “danger”).
  • An allowed variant of Lojban syllabic n, especially in Lojbanized names.
  • The preferred pronunciation of Lojban o. As in the French "haute (cuisine)" or Spanish "como". There is no exact English equivalent of this sound. The nearest GA equivalent is the “o” of “dough” or “joke”, but it is essential that the off-glide (a :[w]-like sound) at the end of the vowel is not pronounced when speaking Lojban. The RP sound in these words is :[əw] in IPA terms, and has no :[o] in it at all; unless you can speak with a Scots, Irish, or American accent, you may have trouble with this sound.
  • An allowed variant of Lojban o, especially before r. This sound is a shortened form of the “aw” in GA “dawn” (for those people who don't pronounce “dawn” and “Don” alike; if you do, you may have trouble with this sound). In RP, but not GA, it is the “o” of “hot”.
  • The preferred pronunciation of Lojban p. As in English “pay”, “super”, or “up”.
  • One version of Lojban r. Not an English sound. The Spanish "rr" and the Scots “r”, a tongue-tip trill.
  • One version of Lojban r. As in GA “right”, “baron”, or “car”. Not found in RP.
  • One version of Lojban r. In GA, appears as a variant of “t” or “d” in the words “metal” and “medal” respectively. A tongue-tip flap.
  • One version of Lojban r. Not an English sound. The French or German "r" in "reine" or "rot" respectively. A uvular trill.
  • are syllabic versions of the above.
[ɹ̩] appears in the GA (but not RP) pronunciation of “bird”.
  • The preferred pronunciation of Lojban s. As in English “so”, “basin”, or “yes”.
  • The preferred pronunciation of Lojban c. The “sh” of English “ship”, “ashen”, or “dish”.
  • An allowed variant of Lojban s. Not an English sound. The Hindi retroflex "s" with dot below, or Klingon "S".
  • The preferred pronunciation of Lojban t. As in English “tea”, “later”, or “not”. It is important to avoid the GA habit of pronouncing the “t” between vowels as :[d] or :[ɾ].
  • Not normally a Lojban sound, but a possible variant of Lojban '. The “th” of English “thin” (but not “then”).
  • The preferred pronunciation of Lojban v. As in English “voice”, “savor”, or “live”.
  • Used in Lojban diphthongs beginning or ending with u. Like the “w” in English “wet” [wɛt] or “cow” [kɑw].
  • The preferred pronunciation of Lojban x. Not normally an English sound, but used in some pronunciations of “loch” and “Bach”; “gh” in Scots “might” and “night”. The German "Ach-Laut". To pronounce :[x], force air through your throat without vibrating your vocal chords; there should be lots of scrape.
  • A possible Lojban buffer vowel. Not an English sound: the "ü" of German "hübsch".
  • The preferred pronunciation of Lojban z. As in English “zoo”, “hazard”, or “fizz”.
  • The preferred pronunciation of Lojban j. The “si” of English “vision”, or the consonant at the end of GA “garage”.
  • An allowed variant of Lojban z. Not an English sound. The voiced version of :[ʂ].

English Analogues For Lojban Diphthongs

Here is a list of English words that contain diphthongs that are similar to the Lojban diphthongs. This list does not constitute an official pronunciation guide; it is intended as a help to English-speakers. <tab class=wikitable header=true>Lojban English ai “pie” ei “pay” oi “boy” au “cow” ia “yard” ie “yes” ii “ye” io “yodel” (in GA only) iu “unicorn” or “few” ua “suave” ue “wet” ui “we” uo “woe” (in GA only) uu “woo” iy “million” (the “io” part, that is) uy “was” (when unstressed) </tab>

Oddball Orthographies

The following notes describe ways in which Lojban has been written or could be written that differ from the standard orthography explained in the rest of this chapter. Nobody needs to read this section except people with an interest in the obscure. Technicalities are used without explanation or further apology.

There exists an alternative orthography for Lojban, which is designed to be as compatible as possible (but no more so) with the orthography used in pre-Lojban versions of Loglan. The consonants undergo no change, except that x is replaced by h. The individual vowels likewise remain unchanged. However, the vowel pairs and diphthongs are changed as follows:

  • ai, ei, oi, au become ai, ei, oi, ao.
  • ia through iu and ua through uu remain unchanged.
  • a'i, e'i, o'i and a'o become a,i, e,i, o,i and a,o.
  • i'a through i'u and u'a through u'u are changed to ia through iu and ua through uu in lujvo and cmavo other than attitudinals, but become i,a through i,u and u,a through u,u in names, fu'ivla, and attitudinal cmavo.
  • All other vowel pairs simply drop the apostrophe.

The result of these rules is to eliminate the apostrophe altogether, replacing it with comma where necessary, and otherwise with nothing. In addition, names and the cmavo i are capitalized, and irregular stress is marked with an apostrophe (now no longer used for a sound) following the stressed syllable.

Three points must be emphasized about this alternative orthography:

  • It is not standard, and has not been used.
  • It does not represent any changes to the standard Lojban phonology; it is simply a representation of the same phonology using a different written form.
  • It was designed to aid in a planned rapprochement between the Logical Language Group and The Loglan Institute, a group headed by James Cooke Brown. The rapprochement never took place.

There also exists a Cyrillic orthography for Lojban which was designed when the introductory Lojban brochure was translated into Russian. It uses the “а”, “б”, “в”, “г”, “д”, “е”, “ж”, “з”, “и”, “к”, “л”, “м”, “н”, “о”, “п”, “р”, “с”, “т”, “у”, “ф”, “х”, and “ш” in the obvious ways. The Latin letter “y” is mapped onto the hard sign “ъ”, as in Bulgarian. The apostrophe, comma, and period are unchanged. Diphthongs are written as vowel pairs, as in the Roman representation.

Finally, an orthography using the Tengwar of Féanor, a fictional orthography invented by J. R. R. Tolkien and described in the Appendixes to The Lord Of The Rings, has been devised for Lojban. The following mapping, which closely resembles that used for Westron, will be meaningful only to those who have read those appendixes. In brief, the tincotéma and parmatéma are used in the conventional ways; the calmatéma represents palatal consonants, and the quessetéma represents velar consonants.


The letters "vala" and "anna" are used for u and i only when those letters are used to represent glides. Of the additional letters, r, l, s, and z are written with "rómen", "lambe", "silme", and "áre"/"esse" respectively; the inverted forms are used as free variants.

Lojban, like Quenya, is a vowel-last language, so tehtar are read as following the tengwar on which they are placed. The conventional tehtar are used for the five regular vowels, and the dot below for y. The Lojban apostrophe is represented by "halla". There is no equivalent of the Lojban comma or period.

Basic sentence elements

The picture for chapter 2

The concept of the bridi

This chapter gives diagrammed examples of basic Lojban sentence structures. The most general pattern is covered first, followed by successive variations on the basic components of the Lojban sentence. There are many more capabilities not covered in this chapter, but covered in detail in later chapters, so this chapter is a “quick tour” of the material later covered more slowly throughout the book. It also introduces most of the Lojban words used to discuss Lojban grammar.

Let us consider John and Sam and three statements about them:

Example 3.1:

John is the father of Sam.
Example 3.2:

John hits Sam.
Example 3.3:

John is taller than Sam.

These examples all describe relationships between John and Sam. However, in English, we use the noun “father” to describe a static relationship in Example 3.1, the verb “hits” to describe an active relationship in Example 3.2, and the adjective “taller” to describe an attributive relationship in Example 3.3. In Lojban we make no such grammatical distinctions; these three sentences, when expressed in Lojban, are structurally identical. The same part of speech is used to represent the relationship. In formal logic this whole structure is called a “predication”; in Lojban it is called a bridi, and the central part of speech is the selbri. Logicians refer to the things thus related as “arguments”, while Lojbanists call them sumti. These Lojban terms will be used for the rest of the book.

bridi (predicate)
|                               |
John     is the father of       Sam
|____|    |______________|      |___|
|              |               |
sumti         selbri          sumti (argument)

In a relationship, there are a definite number of things being related. In English, for example, “give” has three places: the donor, the recipient and the gift. For example:

Example 3.4:

John gives Sam the book.


Example 3.5:

Sam gives John the book.

mean two different things because the relative positions of “John” and “Sam” have been switched. Further,

Example 3.6:

The book gives John Sam.

seems strange to us merely because the places are being filled by unorthodox arguments. The relationship expressed by “give” has not changed.

In Lojban, each selbri has a specified number and type of arguments, known collectively as its “place structure”. The simplest kind of selbri consists of a single root word, called a gismu, and the definition in a dictionary gives the place structure explicitly. The primary task of constructing a Lojban sentence, after choosing the relationship itself, is deciding what you will use to fill in the sumti places.

This book uses the Lojban terms bridi, sumti, and selbri, because it is best to come to understand them independently of the English associations of the corresponding words, which are only roughly similar in meaning anyhow.

The Lojban examples in this chapter (but not in the rest of the book) use a single underline (---) under each sumti, and a double underline (===) under each selbri, to help you to tell them apart.


Detailed pronunciation and spelling rules are given in Chapter 4, but what follows will keep the reader from going too far astray while digesting this chapter.

Lojban has six recognized vowels: a, e, i, o, u and y. The first five are roughly pronounced as “a” as in “father”, e as in “let”, i as in “machine”, o as in “dome” and u as in “flute”. y is pronounced as the sound called “schwa”, that is, as the unstressed “a” as in “about” or “around”.

Twelve consonants in Lojban are pronounced more or less as their counterparts are in English: b, d, f, k, l, m, n, p, r, t, v and z. The letter c, on the other hand is pronounced as the “sh” in “hush”, while j is its voiced counterpart, the sound of the “s” in “pleasure”. g is always pronounced as it is in “gift”, never as in “giant”. s is as in “sell”, never as in “rose”. The sound of x is not found in English in normal words. It is found as "ch" in Scottish "loch", as "j" in Spanish "junta", and as "ch" in German "Bach"; it also appears in the English interjection “yecchh!”. It gets easier to say as you practice it. The letter r can be trilled, but doesn't have to be.

The Lojban diphthongs ai, ei, oi, and au are pronounced much as in the English words “sigh”, “say”, “boy”, and “how”. Other Lojban diphthongs begin with an i pronounced like English “y” (for example, io is pronounced “yo”) or else with a u pronounced like English “w” (for example, ua is pronounced “wa”).

Lojban also has three “semi-letters”: the period, the comma and the apostrophe. The period represents a glottal stop or a pause; it is a required stoppage of the flow of air in the speech stream. The apostrophe sounds just like the English letter “h”. Unlike a regular consonant, it is not found at the beginning or end of a word, nor is it found adjacent to a consonant; it is only found between two vowels. The comma has no sound associated with it, and is used to separate syllables that might ordinarily run together. It is not used in this chapter.

Stress falls on the next to the last syllable of all words, unless that vowel is y, which is never stressed; in such words the third-to-last syllable is stressed. If a word only has one syllable, then that syllable is not stressed.

All Lojban words are pronounced as they are spelled: there are no silent letters.

Words that can act as sumti

Here is a short table of single words used as sumti. This table provides examples only, not the entire set of such words, which may be found in Section 10.15.

mi = '
do = '
ti = '
ta = '
tu = '
zo'e = '

Lojban sumti are not specific as to number (singular or plural), nor gender (masculine/feminine/neutral). Such distinctions can be optionally added by methods that are beyond the scope of this chapter.

The cmavo ti, ta, and tu refer to whatever the speaker is pointing at, and should not be used to refer to things that cannot in principle be pointed at.

Names may also be used as sumti, provided they are preceded with the word la:

la meris.
the one/ones named Mary
la djan.
the one/ones named John

Other Lojban spelling versions are possible for names from other languages, and there are restrictions on which letters may appear in Lojban names: See Section 8.11 for more information.

Some words used to indicate selbri relations

Here is a short table of some words used as Lojban selbri in this chapter:

vecnu = '
tavla = '
sutra = '
blari'o = '
melbi = '
cutci = '
bajra = '
klama = '
pluka = '
gerku = '
kurji = '
kanro = '
stali = '
zarci = '

Each selbri (relation) has a specific rule that defines the role of each sumti in the bridi, based on its position. In the table above, that order was expressed by labeling the sumti positions as x1, x2, x3, x4, and x5.

Like the table in Section 3.3, this table is far from complete: in fact, no complete table can exist, because Lojban allows new words to be created (in specified ways) whenever a speaker or writer finds the existing supply of words inadequate. This notion is a basic difference between Lojban (and some other languages such as German and Chinese) and English; in English, most people are very leery of using words that “aren't in the dictionary”. Lojbanists are encouraged to invent new words; doing so is a major way of participating in the development of the language. Chapter 5 explains how to make new words, and Chapter ELG-ERROR in Template:Lch explains how to give them appropriate meanings.

Some simple Lojban bridi

Let's look at a simple Lojban bridi. The place structure of the gismu tavla is

Example 3.7:

x1 talks to x2 about x3 in language x4

where the “x”-es with following numbers represent the various arguments that could be inserted at the given positions in the English sentence. For example:

Example 3.8:

John talks to Sam about engineering in Lojban.

has “John” in the x1 place, “Sam” in the x2 place, “engineering” in the x3 place, and “Lojban” in the x4 place, and could be paraphrased:

Example 3.9:

Talking is going on, with speaker John and listener Sam and subject matter engineering and language Lojban.

The Lojban bridi corresponding to Example 3.7 will have the form

Example 3.10:

x1 cu tavla x2 x3 x4

The word cu serves as a separator between any preceding sumti and the selbri. It can often be omitted, as in the following examples.

Example 3.11:

mi tavla do zo'e zo'e
I talk to you about something in some language.
Example 3.12:

do tavla mi ta zo'e
You talk to me about that thing in a language.
Example 3.13:

mi tavla zo'e tu ti
I talk to someone about that thing yonder in this language.

(Example 3.13 is a bit unusual, as there is no easy way to point to a language; one might point to a copy of this book, and hope the meaning gets across!)

When there are one or more occurrences of the cmavo zo'e at the end of a bridi, they may be omitted, a process called “ellipsis”. Example 3.11 and Example 3.12 may be expressed thus:

Example 3.14:

mi tavla do
I talk to you (about something in some language).
Example 3.15:

do tavla mi ta
You talk to me about that thing (in some language).

Note that Example 3.13 is not subject to ellipsis by this direct method, as the zo'e in it is not at the end of the bridi.

Variant bridi structure

Consider the sentence

Example 3.16:

mi cu vecnu ti ta zo'e
seller-x1 sells goods-sold-x2 buyer-x3 price-x4
I sell this to that for some price.
I sell this-thing/these-things to that-buyer/those-buyers.
(the price is obvious or unimportant)Example 3.16 has one sumti (the x1) before the selbri. It is also possible to put more than one sumti before the selbri, without changing the order of sumti:
Example 3.17:

mi ti cu vecnu ta
seller-x1 goods-sold-x2 sells buyer-x3
I this sell to that.
(translates as stilted or poetic English)
I this thing do sell to that buyer.
Example 3.18:

mi ti ta cu vecnu
seller-x1 goods-sold-x2 buyer-x3 sells
I this to that sell
(translates as stilted or poetic English)
I this thing to that buyer do sell.

Example 3.16 through Example 3.18 mean the same thing. Usually, placing more than one sumti before the selbri is done for style or for emphasis on the sumti that are out-of-place from their normal position. (Native speakers of languages other than English may prefer such orders.)

If there are no sumti before the selbri, then it is understood that the x1 sumti value is equivalent to zo'e; i.e. unimportant or obvious, and therefore not given. Any sumti after the selbri start counting from x2.

Example 3.19:

ta cu melbi
object/idea-x1 is-beautiful
to someone by some standard
That/Those is/are beautiful.
That is beautiful.:Those are beautiful.when the x1 is omitted, becomes:
Example 3.20:
unspecified-x1 is-beautiful
to someone by some standard
Beautiful!:It's beautiful!

Omitting the x1 adds emphasis to the selbri relation, which has become first in the sentence. This kind of sentence is termed an observative, because it is often used when someone first observes or takes note of the relationship, and wishes to quickly communicate it to someone else. Commonly understood English observatives include “Smoke!” upon seeing smoke or smelling the odor, or “Car!” to a person crossing the street who might be in danger. Any Lojban selbri can be used as an observative if no sumti appear before the selbri.

The word cu does not occur in an observative; cu is a separator, and there must be a sumti before the selbri that needs to be kept separate for cu to be used. With no sumti preceding the selbri, cu is not permitted. Short words like cu which serve grammatical functions are called cmavo in Lojban.

Varying the order of sumti

For one reason or another you may want to change the order, placing one particular sumti at the front of the bridi. The cmavo se, when placed before the last word of the selbri, will switch the meanings of the first and second sumti places. So

Example 3.21:

mi tavla do ti
I talk to you about this.

has the same meaning as

Example 3.22:
do se tavla mi ti
You are talked to by me about this.

The cmavo te, when used in the same location, switches the meanings of the first and the third sumti places.

Example 3.23:
mi tavla do ti
I talk to you about this.has the same meaning as
Example 3.24:
ti te tavla do mi
This is talked about to you by me.

Note that only the first and third sumti have switched places; the second sumti has remained in the second place.

The cmavo ve and xe switch the first and fourth sumti places, and the first and fifth sumti places, respectively. These changes in the order of places are known as “conversions”, and the se, te, ve, and xe cmavo are said to convert the selbri.

More than one of these operators may be used on a given selbri at one time, and in such a case they are evaluated from left to right. However, in practice they are used one at a time, as there are better tools for complex manipulation of the sumti places. See Chapter 6 for details. The effect is similar to what in English is called the “passive voice”. In Lojban, the converted selbri has a new place structure that is renumbered to reflect the place reversal, thus having effects when such a conversion is used in combination with other constructs such as

le selbri [ku] (See Section 3.10).

The basic structure of longer utterances

People don't always say just one sentence. Lojban has a specific structure for talk or writing that is longer than one sentence. The entirety of a given speech event or written text is called an utterance. The sentences (usually, but not always, bridi) in an utterance are separated by the cmavo ni'o and i. These correspond to a brief pause (or nothing at all) in spoken English, and the various punctuation marks like period, question mark, and exclamation mark in written English. These separators prevent the sumti at the beginning of the next sentence from being mistaken for a trailing sumti of the previous sentence.

The cmavo ni'o separates paragraphs (covering different topics of discussion). In a long text or utterance, the topical structure of the text may be indicated by multiple ni'o s, with perhaps

ni'oni'oni'o used to indicate a chapter,
ni'oni'o to indicate a section, and a single ni'o to indicate a subtopic corresponding to a single English paragraph.

The cmavo i separates sentences. It is sometimes compounded with words that modify the exact meaning (the semantics) of the sentence in the context of the utterance. (The cmavo xu, discussed in Section 3.15, is one such word – it turns the sentence from a statement to a question about truth.) When more than one person is talking, a new speaker will usually omit the i even though she/he may be continuing on the same topic.

It is still O.K. for a new speaker to say the i before continuing; indeed, it is encouraged for maximum clarity (since it is possible that the second speaker might merely be adding words onto the end of the first speaker's sentence). A good translation for i is the “and” used in run-on sentences when people are talking informally: “I did this, and then I did that, and ..., and ...”.


When two gismu are adjacent, the first one modifies the second, and the selbri takes its place structure from the rightmost word. Such combinations of gismu are called tanru. For example,

Example 3.25:

sutra tavla

has the place structure

Example 3.26:

x1 is a fast type-of talker to x2 about x3 in language x4
x1 talks fast to x2 about x3 in language x4

When three or more gismu are in a row, the first modifies the second, and that combined meaning modifies the third, and that combined meaning modifies the fourth, and so on. For example

Example 3.27:

sutra tavla cutci

has the place structure

Example 3.28:

s1 is a fast-talker type of shoe worn by s2 of material s3

That is, it is a shoe that is worn by a fast talker rather than a shoe that is fast and is also worn by a talker.

Note especially the use of “type-of” as a mechanism for connecting the English translations of the two or more gismu; this convention helps the learner understand each tanru in its context. Creative interpretations are also possible, however:

Example 3.29:

bajra cutci
runner shoe

most probably refers to shoes suitable for runners, but might be interpreted in some imaginative instances as “shoes that run (by themselves?)”. In general, however, the meaning of a tanru is determined by the literal meaning of its components, and not by any connotations or figurative meanings. Thus

Example 3.30:

sutra tavla

would not necessarily imply any trickery or deception, unlike the English idiom, and a

Example 3.31:

jikca toldi
social butterfly

must always be an insect with large brightly-colored wings, of the family Lepidoptera.

The place structure of a tanru is always that of the final component of the tanru. Thus, the following has the place structure of klama:

Example 3.32:

mi cu sutra klama la meris.
I quickly-go to Mary.

With the conversion se klama as the final component of the tanru, the place structure of the entire selbri is that of se klama: the x1 place is the destination, and the x2 place is the one who goes:

Example 3.33:
mi cu sutra se klama la meris.
I quickly am-gone-to by Mary.

The following example shows that there is more to conversion than merely switching places, though:

Example 3.34:

la tam. cu melbi tavla la meris.
Tom beautifully-talks to Mary.
Tom is a beautiful-talker to Mary.

has the place structure of tavla, but note the two distinct interpretations. Now, using conversion, we can modify the place structure order:

Example 3.35:

la meris. cu melbi se tavla la tam.
Mary is beautifully-talked-to by Tom.
Mary is a beautiful-audience for Tom.

and we see that the modification has been changed so as to focus on Mary's role in the bridi relationship, leading to a different set of possible interpretations.Note that there is no place structure change if the modifying term is converted, and so less drastic variation in possible meanings:

Example 3.36:

la tam. cu tavla melbi la meris.
Tom is talkerly-beautiful to Mary.
Example 3.37:
la tam. cu se tavla melbi la meris.
Tom is audiencely-beautiful to Mary.

and we see that the manner in which Tom is seen as beautiful by Mary changes, but Tom is still the one perceived as beautiful, and Mary, the observer of beauty.

Description sumti

Often we wish to talk about things other than the speaker, the listener and things we can point to. Let's say I want to talk about a talker other than mi. What I want to talk about would naturally fit into the first place of tavla. Lojban, it turns out, has an operator that pulls this first place out of a selbri and converts it to a sumti called a “description sumti”. The description sumti

le tavla ku means “the talker”, and may be used wherever any sumti may be used.

For example,

Example 3.38:

mi tavla do le tavla [ku]

means the same as

Example 3.39:

I talk to you about the talker.

where “the talker” is presumably someone other than me, though not necessarily.


le sutra tavla ku is
“the fast talker”, and
le sutra te tavla ku is
“the fast subject of talk” or
“the subject of fast talk”.

Which of these related meanings is understood will depend on the context in which the expression is used. The most plausible interpretation within the context will generally be assumed by a listener to be the intended one.

In many cases the word ku may be omitted. In particular, it is never necessary in a description at the end of a sentence, so:

Example 3.40:

mi tavla do le tavla
I talk-to you about-the talker

means exactly the same thing as Example 3.38.

There is a problem when we want to say “The fast one is talking.” The “obvious” translation le sutra tavla turns out to mean “the fast talker”, and has no selbri at all. To solve this problem we can use the word cu, which so far has always been optional, in front of the selbri.

The word cu has no meaning, and exists only to mark the beginning of the selbri within the bridi, separating it from a previous sumti. It comes before any other part of the selbri, including other cmavo like se or te. Thus:

Example 3.41:

le sutra tavla
The fast talker
Example 3.42:
le sutra cu tavla
The fast one is talking.
Example 3.43::le sutra se tavla
The fast talked-to one
Example 3.44:
le sutra cu se tavla
The fast one is talked to.

Consider the following more complex example, with two description sumti.

Example 3.45:
mi cu tavla le vecnu ku le blari'o ku
I talk-to the seller about the blue-green-thing.

The sumti le vecnu contains the selbri vecnu, which has the “seller” in the x1 place, and uses it in this sentence to describe a particular “seller” that the speaker has in mind (one that he or she probably expects the listener will also know about). Similarly, the speaker has a particular blue-green thing in mind, which is described using le to mark blari'o, a selbri whose first sumti is something blue-green.

It is safe to omit both occurrences of ku in Example 3.45, and it is also safe to omit the cu.

Examples of brivla

The simplest form of selbri is an individual word. A word which may by itself express a selbri relation is called a brivla. The three types of brivla are gismu (root words), lujvo (compounds), and fu'ivla (borrowings from other languages). All have identical grammatical uses. So far, most of our selbri have been gismu or tanru built from gismu.


Example 3.46:

mi cu klama ti zo'e zo'e ta
Go-er goes destination origin route means.
I go here (to this) using that means (from somewhere via some route). lujvo:
Example 3.47:
ta cu blari'o
That is-blue-green.


Example 3.48:
ti cu djarspageti
This is-spaghetti.

Some cmavo may also serve as selbri, acting as variables that stand for another selbri. The most commonly used of these is go'i, which represents the main bridi of the previous Lojban sentence, with any new sumti or other sentence features being expressed replacing the previously expressed ones. Thus, in this context:

Example 3.49:
ta cu go'i
That too/same-as-last selbri.
That (is spaghetti), too.

The sumti di'u and la'e di'u

In English, I might say “The dog is beautiful”, and you might reply “This pleases me.” How do you know what “this” refers to? Lojban uses different expressions to convey the possible meanings of the English:

Example 3.50:

le gerku ku cu melbi
The dog is beautiful.The following three sentences all might translate as “This pleases me.”
Example 3.51:
ti cu pluka mi
This (the dog) pleases me.
Example 3.52:
di'u cu pluka mi
This (the last sentence) pleases me (perhaps because it is grammatical or sounds nice).
Example 3.53:
la'e di'u cu pluka mi
This (the meaning of the last sentence; i.e. that the dog is beautiful) pleases me. Example 3.53 uses one sumti to point to or refer to another by inference. It is common to write la'edi'u as a single word; it is used more often than di'u by itself.


“Possession” refers to the concept of specifying an object by saying who it belongs to (or with). A full explanation of Lojban possession is given in Chapter 12. A simple means of expressing possession, however, is to place a sumti representing the possessor of an object within the description sumti that refers to the object: specifically, between the le and the selbri of the description:

Example 3.54:

le mi gerku cu sutra
The of-me dog is fast.
My dog is fast.

In Lojban, possession doesn't necessarily mean ownership: one may “possess” a chair simply by sitting on it, even though it actually belongs to someone else. English uses possession casually in the same way, but also uses it to refer to actual ownership or even more intimate relationships: “my arm” doesn't mean “some arm I own” but rather “the arm that is part of my body”. Lojban has methods of specifying all these different kinds of possession precisely and easily.

Vocatives and commands

You may call someone's attention to the fact that you are addressing them by using doi followed by their name. The sentence

Example 3.55:

doi djan.

means “Oh, John, I'm talking to you”. It also has the effect of setting the value of do; do now refers to “John” until it is changed in some way in the conversation. Note that Example 3.55 is not a bridi, but it is a legitimate Lojban sentence nevertheless; it is known as a “vocative phrase”.

Other cmavo can be used instead of doi in a vocative phrase, with a different significance. For example, the cmavo coi means “hello” and co'o means “good-bye”. Either word may stand alone, they may follow one another, or either may be followed by a pause and a name. (Vocative phrases with doi do not need a pause before the name.)

Example 3.56:

coi. djan.
Hello, John.
Example 3.57:

co'o. djan.
Good-bye, John.

Commands are expressed in Lojban by a simple variation of the main bridi structure. If you say

Example 3.58:

do tavla
You are-talking.

you are simply making a statement of fact. In order to issue a command in Lojban, substitute the word ko for do. The bridi

Example 3.59:
ko tavla instructs the listener to do whatever is necessary to make Example 3.58 true; it means “Talk!” Other examples:
Example 3.60:
ko sutra
Be fast!

The ko need not be in the x1 place, but rather can occur anywhere a sumti is allowed, leading to possible Lojban commands that are very unlike English commands:

Example 3.61:
mi tavla ko
Be talked to by me.:Let me talk to you.The cmavo ko can fill any appropriate sumti place, and can be used as often as is appropriate for the selbri:
Example 3.62:
ko kurji koand
Example 3.63:
ko ko kurjiboth mean “You take care of you” and “Be taken care of by you”, or to put it colloquially, “Take care of yourself”.


There are many kinds of questions in Lojban: full explanations appear in Section 18.48 and in various other chapters throughout the book. In this chapter, we will introduce three kinds: sumti questions, selbri questions, and yes/no questions.

The cmavo ma is used to create a sumti question: it indicates that the speaker wishes to know the sumti which should be placed at the location of the ma to make the bridi true. It can be translated as “Who?” or “What?” in most cases, but also serves for “When?”, “Where?”, and “Why?” when used in sumti places that express time, location, or cause. For example:

Example 3.64:

ma tavla do mi
Who? talks to-you about-me.
Who is talking to you about me?The listener can reply by simply stating a sumti:
Example 3.65:: la djan.
John (is talking to you about me).Like ko, ma can occur in any position where a sumti is allowed, not just in the first position:
Example 3.66:
do cu tavla ma
You talk to what/whom?

A ma can also appear in multiple sumti positions in one sentence, in effect asking several questions at once.

Example 3.67:
ma cu tavla ma
What/Who talks to what/whom?

The two separate ma positions ask two separate questions, and can therefore be answered with different values in each sumti place. The cmavo mo is the selbri analogue of ma. It asks the respondent to provide a selbri that would be a true relation if inserted in place of the mo:

Example 3.68:

do cu mo
You are-what/do-what?

A mo may be used anywhere a brivla or other selbri might. Keep this in mind for later examples. Unfortunately, by itself, mo is a very non-specific question. The response to the question in Example 3.68 could be:

Example 3.69:
mi cu melbi
I am beautiful.or:
Example 3.70:
mi cu tavla
I talk.

Clearly, mo requires some cooperation between the speaker and the respondent to ensure that the right question is being answered. If context doesn't make the question specific enough, the speaker must ask the question more specifically using a more complex construction such as a tanru (See Section 3.9).

It is perfectly permissible for the respondent to fill in other unspecified places in responding to a mo question. Thus, the respondent in Example 3.70 could have also specified an audience, a topic, and/or a language in the response.

Finally, we must consider questions that can be answered “Yes” or “No”, such as

Example 3.71:

Are you talking to me?

Like all yes-or-no questions in English, Example 3.71 may be reformulated as

Example 3.72:

Is it true that you are talking to me?

In Lojban we have a word that asks precisely that question in precisely the same way. The cmavo xu, when placed in front of a bridi, asks whether that bridi is true as stated. So

Example 3.73:

xu do tavla mi
Is-it-true-that you are-talking to-me?

is the Lojban translation of Example 3.71. The answer “Yes” may be given by simply restating the bridi without the xu question word. Lojban has a shorthand for doing this with the word go'i, mentioned in Section 3.11. Instead of a negative answer, the bridi may be restated in such a way as to make it true. If this can be done by substituting sumti, it may be done with go'i as well. For example:

Example 3.74:

xu do kanro
Are you healthy?

can be answered with

Example 3.75:
mi kanro
I am healthy.or
Example 3.76:
I am healthy.(Note that do to the questioner is mi to the respondent.)or
Example 3.77:
le tavla cu kanro
The talker is healthy.or
Example 3.78:
le tavla cu go'i
The talker is healthy. A general negative answer may be given by na go'i. na may be placed before any selbri (but after the cu). It is equivalent to stating “It is not true that ...” before the bridi. It does not imply that anything else is true or untrue, only that that specific bridi is not true. More details on negative statements are available in Chapter ELG-ERROR in Template:Lch.


Different cultures express emotions and attitudes with a variety of intonations and gestures that are not usually included in written language. Some of these are available in some languages as interjections (i.e. Aha!, Oh no!, Ouch!, Aahh!, etc.), but they vary greatly from culture to culture.</para>

Lojban has a group of cmavo known as “attitudinal indicators” which specifically covers this type of commentary on spoken statements. They are both written and spoken, but require no specific intonation or gestures. Grammatically they are very simple: one or more attitudinals at the beginning of a bridi apply to the entire bridi; anywhere else in the bridi they apply to the word immediately to the left. For example:

Example 3.79:

.ie mi cu klama
Agreement! I go.
Yep! I'll go.
Example 3.80:
.ei mi cu klama
Obligation! I go.
I should go.
Example 3.81:
mi cu klama le melbi .ui ku
I go to-the beautiful-thing and I am happy because it is the beautiful thing I'm going to

Not all indicators indicate attitudes. Discursives, another group of cmavo with the same grammatical rules as attitudinal indicators, allow free expression of certain kinds of commentary about the main utterances. Using discursives allows a clear separation of these so-called “metalinguistic” features from the underlying statements and logical structure. By comparison, the English words “but” and “also”, which discursively indicate contrast or an added weight of example, are logically equivalent to “and”, which does not have a discursive content. The average English-speaker does not think about, and may not even realize, the paradoxical idea that “but” basically means “and”.

Example 3.82:

mi cu klama .i do cu stali
I go. [[:Category:|]] You stay.
Example 3.83:
mi cu klama .i ji'a do cu stali
I go. [[:Category:|]]In addition, you stay. added weight
Example 3.84:

mi cu klama .i ku'i do cu stali
I go. However, you stay.contrast

Another group of indicators are called “evidentials”. Evidentials show the speaker's relationship to the statement, specifically how the speaker came to make the statement. These include za'a (I directly observe the relationship), pe'i (I believe that the relationship holds), ru'a (I postulate the relationship), and others. Many American Indian languages use this kind of words.

Example 3.85:

pe'i do cu melbi
I opine! You are beautiful.
Example 3.86:
za'a do cu melbi
I directly observe! You are beautiful.


In English, every verb is tagged for the grammatical category called tense: past, present, or future. The sentence

Example 3.87:

John went to the store

necessarily happens at some time in the past, whereas

Example 3.88:

John is going to the store

is necessarily happening right now.

The Lojban sentence

Example 3.89:

la djan. cu klama le zarci
John goes/went/will-go to-the store

serves as a translation of either Example 3.87 or Example 3.88, and of many other possible English sentences as well. It is not marked for tense, and can refer to an event in the past, the present or the future. This rule does not mean that Lojban has no way of representing the time of an event. A close translation of Example 3.87 would be:

Example 3.90:
la djan. pu klama le zarci
John [[:Category:[past]|[past]]] goes to-the store

where the tag pu forces the sentence to refer to a time in the past. Similarly,

Example 3.91:

la djan. ca klama le zarci
John [[:Category:[present]|[present]]] goes to-the store

necessarily refers to the present, because of the tag ca. Tags used in this way always appear at the very beginning of the selbri, just after the cu, and they may make a cu unnecessary, since tags cannot be absorbed into tanru. Such tags serve as an equivalent to English tenses and adverbs. In Lojban, tense information is completely optional. If unspecified, the appropriate tense is picked up from context. Lojban also extends the notion of “tense” to refer not only to time but to space. The following example uses the tag vu to specify that the event it describes happens far away from the speaker:

Example 3.92:

do vu vecnu zo'e
You yonder sell something-unspecified.

In addition, tense tags (either for time or space) can be prefixed to the selbri of a description, producing a tensed sumti:

Example 3.93:
le pu bajra ku cu tavla
The earlier/former/past runner talked/talks.

(Since Lojban tense is optional, we don't know when he or she talks.)Tensed sumti with space tags correspond roughly to the English use of “this” or “that” as adjectives, as in the following example, which uses the tag vi meaning “nearby”:

Example 3.94:

le vi bajra ku cu tavla
The nearby runner talks.
This runner talks.

Do not confuse the use of vi in Example 3.94 with the cmavo ti, which also means “this”, but in the sense of “this thing”.

Furthermore, a tense tag can appear both on the selbri and within a description, as in the following example (where ba is the tag for future time):

Example 3.95:

le vi tavla ku cu ba klama
The here talker [future] goes.
The talker who is here will go.:This talker will go.

Lojban grammatical terms

Here is a review of the Lojban grammatical terms used in this chapter, plus some others used throughout this book. Only terms that are themselves Lojban words are included: there are of course many expressions like “indicator” in Chapter 17 that are not explained here. See the Index for further help with these.

  • predication; the basic unit of Lojban expression; the main kind of Lojban sentence; a claim that some objects stand in some relationship, or that some single object has some property.
  • argument; words identifying something which stands in a specified relationship to something else, or which has a specified property. See Chapter 8.
  • logical predicate; the core of a bridi; the word or words specifying the relationship between the objects referred to by the sumti. See Chapter 6.
  • one of the Lojban parts of speech; a short word; a structural word; a word used for its grammatical function.
  • one of the Lojban parts of speech; a content word; a predicate word; can function as a selbri; is a gismu, a lujvo, or a fu'ivla. See

Chapter 5.

  • a root word; a kind of brivla; has associated rafsi. See Chapter 5.
  • a borrowed word; a kind of brivla; may or may not appear in a dictionary; copied in a modified form from some non-Lojban language; usually refers to some aspect of culture or the natural world; does not have associated rafsi. See

Chapter 5.

  • a word fragment; one or more is associated with each gismu; can be assembled according to rules in order to make lujvo; not a valid word by itself. See Chapter 5.
  • a group of two or more brivla, possibly with associated cmavo, that form a selbri; always divisible into two parts, with the first part modifying the meaning of the second part (which is taken to be basic). See Chapter 6.
  • a group of cmavo that have the same grammatical use (can appear interchangeably in sentences, as far as the grammar is concerned) but differ in meaning or other usage. See Chapter ELG-ERROR in Template:Lch.



Morphology is the part of grammar that deals with the form of words. Lojban's morphology is fairly simple compared to that of many languages, because Lojban words don't change form depending on how they are used. English has only a small number of such changes compared to languages like Russian, but it does have changes like “boys” as the plural of “boy”, or “walked” as the past-tense form of “walk”. To make plurals or past tenses in Lojban, you add separate words to the sentence that express the number of boys, or the time when the walking was going on.

However, Lojban does have what is called “derivational morphology”: the capability of building new words from old words. In addition, the form of words tells us something about their grammatical uses, and sometimes about the means by which they entered the language. Lojban has very orderly rules for the formation of words of various types, both the words that already exist and new words yet to be created by speakers and writers.

A stream of Lojban sounds can be uniquely broken up into its component words according to specific rules. These so-called “morphology rules” are summarized in this chapter. (However, a detailed algorithm for breaking sounds into words has not yet been fully debugged, and so is not presented in this book.) First, here are some conventions used to talk about groups of Lojban letters, including vowels and consonants.

  • V represents any single Lojban vowel except y; that is, it represents a, e, i, o, or u.
  • VV represents either a diphthong, one of the following:
    • 'ai'
    • 'ei'
    • 'oi'
    • 'au'
    or a two-syllable vowel pair with an apostrophe separating the vowels, one of the following:
    • 'a'a'
    • 'a'e'
    • 'a'i'
    • 'a'o'
    • 'a'u'
    • 'e'a'
    • 'e'e'
    • 'e'i'
    • 'e'o'
    • 'e'u'
    • 'i'a'
    • 'i'e'
    • 'i'i'
    • 'i'o'
    • 'i'u'
    • 'o'a'
    • 'o'e'
    • 'o'i'
    • 'o'o'
    • 'o'u'
    • 'u'a'
    • 'u'e'
    • 'u'i'
    • 'u'o'
    • 'u'u'
  • C represents a single Lojban consonant, not including the apostrophe, one of
  • b
  • c
  • d
  • f
  • g
  • j
  • k
  • l
  • m
  • n
  • p
  • r
  • s
  • t
  • v
  • x
  • or z.

Syllabic l, m, n, and r always count as consonants for the purposes of this chapter.

  • CC represents two adjacent consonants of type C which constitute one of the 48 permissible initial consonant pairs:
bl br
cf ck cl cm cn cp cr ct
dj dr dz
fl fr
gl gr
jb jd jg jm jv
kl kr
ml mr
pl pr
sf sk sl sm sn sp sr st
tc tr ts
vl vr 
xl xr
zb zd zg zm zv
  • C/C represents two adjacent consonants which constitute one of the permissible consonant pairs (not necessarily a permissible initial consonant pair). The permissible consonant pairs are explained in Section 2.3. In brief, any consonant pair is permissible unless it: contains two identical letters, contains both a voiced (excluding r, l, m, n) and an unvoiced consonant, or is one of certain specified forbidden pairs.
  • C/CC represents a consonant triple. The first two consonants must constitute a permissible consonant pair; the last two consonants must constitute a permissible initial consonant pair.

Lojban has three basic word classes – parts of speech – in contrast to the eight that are traditional in English. These three classes are called cmavo, brivla, and cmene. Each of these classes has uniquely identifying properties – an arrangement of letters that allows the word to be uniquely and unambiguously recognized as a separate word in a string of Lojban, upon either reading or hearing, and as belonging to a specific word-class.

They are also functionally different: cmavo are the structure words, corresponding to English words like “and”, “if”, “the” and “to”; brivla are the content words, corresponding to English words like “come”, “red”, “doctor”, and “freely”; cmene are proper names, corresponding to English “James”, “Afghanistan”, and “Pope John Paul II”.


The first group of Lojban words discussed in this chapter are the cmavo. They are the structure words that hold the Lojban language together. They often have no semantic meaning in themselves, though they may affect the semantics of brivla to which they are attached. The cmavo include the equivalent of English articles, conjunctions, prepositions, numbers, and punctuation marks. There are over a hundred subcategories of cmavo, known as selma'o, each having a specifically defined grammatical usage. The various selma'o are discussed throughout Chapter 6 to Chapter ELG-ERROR in Template:Lch and summarized in Chapter ELG-ERROR in Template:Lch.

Standard cmavo occur in four forms defined by their word structure. Here are some examples of the various forms: <tab class=wikitable header=true> V-form .a .e .i .o .u CV-form ba ce di fo gu VV-form .au .ei .ia o'u u'e CVV-form ki'a pei mi'o coi cu'u </tab> In addition, there is the cmavo .y. (remember that y is not a V), which must have pauses before and after it.

A simple cmavo thus has the property of having only one or two vowels, or of having a single consonant followed by one or two vowels. Words consisting of three or more vowels in a row, or a single consonant followed by three or more vowels, are also of cmavo form, but are reserved for experimental use: a few examples are

sau'e, and
bai'ai. All CVV cmavo beginning with the letter x are also reserved for experimental use. In general, though, the form of a cmavo tells you little or nothing about its grammatical use.

“Experimental use” means that the language designers will not assign any standard meaning or usage to these words, and words and usages coined by Lojban speakers will not appear in official dictionaries for the indefinite future. Experimental-use words provide an escape hatch for adding grammatical mechanisms (as opposed to semantic concepts) the need for which was not foreseen.

The cmavo of VV-form include not only the diphthongs and vowel pairs listed in Section , but also the following ten additional diphthongs:

  • .ia
  • .ie
  • .ii
  • .io
  • .iu
  • .ua
  • .ue
  • .ui
  • .uo
  • .uu

In addition, cmavo can have the form Cy, a consonant followed by the letter y. These cmavo represent letters of the Lojban alphabet, and are discussed in detail in Chapter 18.

Compound cmavo are sequences of cmavo attached together to form a single written word. A compound cmavo is always identical in meaning and in grammatical use to the separated sequence of simple cmavo from which it is composed. These words are written in compound form merely to save visual space, and to ease the reader's burden in identifying when the component cmavo are acting together.

Compound cmavo, while not visually short like their components, can be readily identified by two characteristics:

  • They have no consonant pairs or clusters, and
  • They end in a vowel.

For example:

.i se ci'i
ki'e .u'e

The cmavo u'e begins with a vowel, and like all words beginning with a vowel, requires a pause (represented by .) before it. This pause cannot be omitted simply because the cmavo is incorporated into a compound cmavo. On the other hand,


is a single cmavo reserved for experimental purposes: it has four vowels.

cy. .ibu .abu

Again the pauses are required (See Section 5.8); the pause after cy. merges with the pause before .ibu.

There is no particular stress required in cmavo or their compounds. Some conventions do exist that are not mandatory. For two-syllable cmavo, for example, stress is typically placed on the first vowel; an example is

.e'o ko ko kurji
.E'o ko ko KURji

This convention results in a consistent rhythm to the language, since brivla are required to have penultimate stress; some find this esthetically pleasing.

If the final syllable of one word is stressed, and the first syllable of the next word is stressed, you must insert a pause or glottal stop between the two stressed syllables. Thus

le re nanmu

can be optionally pronounced

le RE. NANmu

since there are no rules forcing stress on either of the first two words; the stress on re, though, demands that a pause separate re from the following syllable

nan to ensure that the stress on
nan is properly heard as a stressed syllable. The alternative pronunciation

LE re NANmu

is also valid; this would apply secondary stress (used for purposes of emphasis, contrast or sentence rhythm) to le, comparable in rhythmical effect to the English phrase “THE two men”. In Example , the secondary stress on re would be similar to that in the English phrase “the TWO men”.

Both cmavo may also be left unstressed, thus:

le re NANmu

This would probably be the most common usage.


Predicate words, called brivla, are at the core of Lojban. They carry most of the semantic information in the language. They serve as the equivalent of English nouns, verbs, adjectives, and adverbs, all in a single part of speech.

Every brivla belongs to one of three major subtypes. These subtypes are defined by the form, or morphology, of the word – all words of a particular structure can be assigned by sight or sound to a particular type (cmavo, brivla, or cmene) and subtype. Knowing the type and subtype then gives you, the reader or listener, significant clues to the meaning and the origin of the word, even if you have never heard the word before.

The same principle allows you, when speaking or writing, to invent new brivla for new concepts “on the fly”; yet it offers people that you are trying to communicate with a good chance to figure out your meaning. In this way, Lojban has a flexible vocabulary which can be expanded indefinitely.

All brivla have the following properties:

  • always end in a vowel;
  • always contain a consonant pair in the first five letters, where y and apostrophe are not counted as letters for this purpose (See Section 5.5.);
  • always are stressed on the next-to-the-last (penultimate) syllable; this implies that they have two or more syllables.

The presence of a consonant pair distinguishes brivla from cmavo and their compounds. The final vowel distinguishes brivla from cmene, which always end in a consonant. Thus

da'amei must be a compound cmavo because it lacks a consonant pair; lojban. must be a name because it lacks a final vowel.

Thus, bisycla has the consonant pair sc in the first five non- y letters even though the sc actually appears in the form of sy.. Similarly, the word ro'inre'o contains nr in the first five letters because the apostrophes are not counted for this purpose.

The three subtypes of brivla are:

  • gismu, the Lojban primitive roots from which all other brivla are built;
  • lujvo, the compounds of two or more gismu; and
  • fu'ivla (literally “copy-word”), the specialized words that are not Lojban primitives or natural compounds, and are therefore borrowed from other languages.


The gismu, or Lojban root words, are those brivla representing concepts most basic to the language. The gismu were chosen for various reasons: some represent concepts that are very familiar and basic; some represent concepts that are frequently used in other languages; some were added because they would be helpful in constructing more complex words; some because they represent fundamental Lojban concepts (like cmavo and gismu themselves).

The gismu do not represent any sort of systematic partitioning of semantic space. Some gismu may be superfluous, or appear for historical reasons: the gismu list was being collected for almost 35 years and was only weeded out once. Instead, the intention is that the gismu blanket semantic space: they make it possible to talk about the entire range of human concerns.

There are about 1350 gismu. In learning Lojban, you need only to learn most of these gismu and their combining forms (known as rafsi) as well as perhaps 200 major cmavo, and you will be able to communicate effectively in the language. This may sound like a lot, but it is a small number compared to the vocabulary needed for similar communications in other languages.

All gismu have very strong form restrictions. Using the conventions defined in Section , all gismu are of the forms CVC/CV or CCVCV. They must meet the rules for all brivla given in Section 5.2; furthermore, they:

  • always have five letters;
  • always start with a consonant and end with a single vowel;
  • always contain exactly one consonant pair, which is a permissible initial pair (CC) if it's at the beginning of the gismu, but otherwise only has to be a permissible pair (C/C);
  • are always stressed on the first syllable (since that is penultimate).

The five letter length distinguishes gismu from lujvo and fu'ivla. In addition, no gismu contains '.

With the exception of five special brivla variables, broda, brode, brodi, brodo, and brodu, no two gismu differ only in the final vowel. Furthermore, the set of gismu was specifically designed to reduce the likelihood that two similar sounding gismu could be confused. For example, because gismu is in the set of gismu, kismu, xismu, gicmu, gizmu, and gisnu cannot be.

Almost all Lojban gismu are constructed from pieces of words drawn from other languages, specifically Chinese, English, Hindi, Spanish, Russian, and Arabic, the six most widely spoken natural languages. For a given concept, words in the six languages that represent that concept were written in Lojban phonetics. Then a gismu was selected to maximize the recognizability of the Lojban word for speakers of the six languages by weighting the inclusion of the sounds drawn from each language by the number of speakers of that language. See Section 5.13 for a full explanation of the algorithm.

Here are a few examples of gismu, with rough English equivalents (not definitions):


A small number of gismu were formed differently; See Section 5.14 for a list.


When specifying a concept that is not found among the gismu (or, more specifically, when the relevant gismu seems too general in meaning), a Lojbanist generally attempts to express the concept as a tanru. Lojban tanru are an elaboration of the concept of “metaphor” used in English. In Lojban, any brivla can be used to modify another brivla. The first of the pair modifies the second. This modification is usually restrictive – the modifying brivla reduces the broader sense of the modified brivla to form a more narrow, concrete, or specific concept. Modifying brivla may thus be seen as acting like English adverbs or adjectives. For example,

skami pilno

is the tanru which expresses the concept of “computer user”.

The simplest Lojban tanru are pairings of two concepts or ideas. Such tanru take two simpler ideas that can be represented by gismu and combine them into a single more complex idea. Two-part tanru may then be recombined in pairs with other tanru, or with individual gismu, to form more complex or more specific ideas, and so on.

The meaning of a tanru is usually at least partly ambiguous:

skami pilno could refer to a computer that is a user, or to a user of computers. There are a variety of ways that the modifier component can be related to the modified component. It is also possible to use cmavo within tanru to provide variations (or to prevent ambiguities) of meaning.

Making tanru is essentially a poetic or creative act, not a science. While the syntax expressing the grouping relationships within tanru is unambiguous, tanru are still semantically ambiguous, since the rules defining the relationships between the gismu are flexible. The process of devising a new tanru is dealt with in detail in Chapter 6.

To express a simple tanru, simply say the component gismu together. Thus the binary metaphor “big boat” becomes the tanru

barda bloti

representing roughly the same concept as the English word “ship”.

The binary metaphor “father mother” can refer to a paternal grandmother ( “a father-ly type of mother”), while “mother father” can refer to a maternal grandfather ( “a mother-ly type of father”). In Lojban, these become the tanru

patfu mamta


mamta patfu


The possibility of semantic ambiguity can easily be seen in the last case. To interpret Example , the listener must determine what type of motherliness pertains to the father being referred to. In an appropriate context,

mamta patfu could mean not “grandfather” but simply “father with some motherly attributes”, depending on the culture. If absolute clarity is required, there are ways to expand upon and explain the exact interrelationship between the components; but such detail is usually not needed.

When a concept expressed in a tanru proves useful, or is frequently expressed, it is desirable to choose one of the possible meanings of the tanru and assign it to a new brivla. For Example , we would probably choose “user of computers”, and form the new word


Such a brivla, built from the rafsi which represent its component words, is called a lujvo. Another example, corresponding to the tanru of Example , would be:


The lujvo representing a given tanru is built from units representing the component gismu. These units are called rafsi in Lojban. Each rafsi represents only one gismu. The rafsi are attached together in the order of the words in the tanru, occasionally inserting so-called “hyphen” letters to ensure that the pieces stick together as a single word and cannot accidentally be broken apart into cmavo, gismu, or other word forms. As a result, each lujvo can be readily and accurately recognized, allowing a listener to pick out the word from a string of spoken Lojban, and if necessary, unambiguously decompose the word to a unique source tanru, thus providing a strong clue to its meaning.

The lujvo that can be built from the tanru

mamta patfu in Example is

which refers specifically to the concept “maternal grandfather”. The two gismu that constitute the tanru are represented in mampa'u by the rafsi mam- and -pa'u, respectively; these two rafsi are then concatenated together to form mampa'u.

Like gismu, lujvo have only one meaning. When a lujvo is formally entered into a dictionary of the language, a specific definition will be assigned based on one particular interrelationship between the terms. (See Chapter ELG-ERROR in Template:Lch for how this has been done.) Unlike gismu, lujvo may have more than one form. This is because there is no difference in meaning between the various rafsi for a gismu when they are used to build a lujvo. A long rafsi may be used, especially in noisy environments, in place of a short rafsi; the result is considered the same lujvo, even though the word is spelled and pronounced differently. Thus the word brivla, built from the tanru :bridi valsi, is the same lujvo as brivalsi, bridyvla, and bridyvalsi, each of which uses a different combination of rafsi.

When assembling rafsi together into lujvo, the rules for valid brivla must be followed: a consonant cluster must occur in the first five letters (excluding y and '), and the lujvo must end in a vowel.

A y (which is ignored in determining stress or consonant clusters) is inserted in the middle of the consonant cluster to glue the word together when the resulting cluster is either not permissible or the word is likely to break up. There are specific rules describing these conditions, detailed in Section 5.5.

An r (in some cases, an n) is inserted when a CVV-form rafsi attaches to the beginning of a lujvo in such a way that there is no consonant cluster. For example, in the lujvo

sonci sanmi
soldier meal
field rations

the rafsi soi- and -sai are joined, with the additional r making up the rs consonant pair needed to make the word a brivla. Without the r, the word would break up into

soi sai, two cmavo. The pair of cmavo have no relation to their rafsi lookalikes; they will either be ungrammatical (as in this case), or will express a different meaning from what was intended.

Learning rafsi and the rules for assembling them into lujvo is clearly seen to be necessary for fully using the potential Lojban vocabulary.

Most important, it is possible to invent new lujvo while you speak or write in order to represent a new or unfamiliar concept, one for which you do not know any existing Lojban word. As long as you follow the rules for building these compounds, there is a good chance that you will be understood without explanation.


Every gismu has from two to five rafsi, each of a different form, but each such rafsi represents only one gismu. It is valid to use any of the rafsi forms in building lujvo – whichever the reader or listener will most easily understand, or whichever is most pleasing – subject to the rules of lujvo making. There is a scoring algorithm which is intended to determine which of the possible and legal lujvo forms will be the standard dictionary form (See Section 5.11).

Each gismu always has at least two rafsi forms; one is the gismu itself (used only at the end of a lujvo), and one is the gismu without its final vowel (used only at the beginning or middle of a lujvo). These forms are represented as CVC/CV or CCVCV (called “the 5-letter rafsi”), and CVC/C or CCVC (called “the 4-letter rafsi”) respectively. The dashes in these rafsi form representations show where other rafsi may be attached to form a valid lujvo. When lujvo are formed only from 4-letter and 5-letter rafsi, known collectively as “long rafsi”, they are called “unreduced lujvo”.

Some examples of unreduced lujvo forms are:

mamta patfu
“mother father”
or “maternal grandfather”
lerfu liste
“letter list” or a “list of letters”
(letters of the alphabet)
nanca prali
“year profit”
or “annual profit”
pruni plipe
“elastic (springy) leap”
or “spring” (the verb)

vanci sanmi
“evening meal”
or “supper”

In addition to these two forms, each gismu may have up to three additional short rafsi, three letters long. All short rafsi have one of the forms CVC, CCV, or CVV. The total number of rafsi forms that are assigned to a gismu depends on how useful the gismu is, or is presumed to be, in making lujvo, when compared to other gismu that could be assigned the rafsi.

For example, zmadu ( “more than”) has the two short rafsi zma and mau (in addition to its unreduced rafsi

zmad and zmadu), because a vast number of lujvo have been created based on zmadu, corresponding in general to English comparative adjectives ending in “-er” such as “whiter” (Lojban labmau). On the other hand, bakri (“chalk”) has no short rafsi and few lujvo.

There are at most one CVC-form, one CCV-form, and one CVV-form rafsi per gismu. In fact, only a tiny handful of gismu have both a CCV-form and a CVV-form rafsi assigned, and still fewer have all three forms of short rafsi. However, gismu with both a CVC-form and another short rafsi are fairly common, partly because more possible CVC-form rafsi exist. Yet CVC-form rafsi, even though they are fairly easy to remember, cannot be used at the end of a lujvo (because lujvo must end in vowels), so justifying the assignment of an additional short rafsi to many gismu.

The intention was to use the available “rafsi space”- the set of all possible short rafsi forms – in the most efficient way possible; the goal is to make the most-used lujvo as short as possible (thus maximizing the use of short rafsi), while keeping the rafsi very recognizable to anyone who knows the source gismu. For this reason, the letters in a rafsi have always been chosen from among the five letters of the corresponding gismu. As a result, there are a limited set of short rafsi available for assignment to each gismu. At most seven possible short rafsi are available for consideration (of which at most three can be used, as explained above).

Here are the only short rafsi forms that can possibly exist for gismu of the form CVC/CV, like sakli. The digits in the second column represent the gismu letters used to form the rafsi. <tab class=wikitable header=true>CVC 123 -sak- CVC 124 -sal- CVV 12'5 -sa'i- CVV 125 -sai- CCV 345 -kli- CCV 132 -ska- </tab> (The only actual short rafsi for sakli is -sal-.)

For gismu of the form CCVCV, like blaci, the only short rafsi forms that can exist are: <tab class=wikitable header=true>CVC 134 -bac- CVC 234 -lac CVV 13'5 -ba'i- CVV 135 -bai- CVV 23'5 -la'i- CVV 235 -lai- CCV 123 -bla- </tab> (In fact, blaci has none of these short rafsi; they are all assigned to other gismu. Lojban speakers are not free to reassign any of the rafsi; the tables shown here are to help understand how the rafsi were chosen in the first place.)

There are a few restrictions: a CVV-form rafsi without an apostrophe cannot exist unless the vowels make up one of the four diphthongs ai, ei, oi, or au; and a CCV-form rafsi is possible only if the two consonants form a permissible initial consonant pair (See Section ). Thus mamta, which has the same form as salci, can only have mam, mat, and ma'a as possible rafsi: in fact, only mam is assigned to it.

Some cmavo also have associated rafsi, usually CVC-form. For example, the ten common numerical digits, which are all CV form cmavo, each have a CVC-form rafsi formed by adding a consonant to the cmavo. Most cmavo that have rafsi are ones used in composing tanru.

The term for a lujvo made up solely of short rafsi is “fully reduced lujvo”. Here are some examples of fully reduced lujvo:

cumki lifri
“possible experience”

klesi zbasu
“category make”

krixa tavla
“cry-out talk”

sinxa djuno
“sign know”

In addition, the unreduced forms in Example and Example may be fully reduced to:

mamta patfu
“mother father”
or “maternal grandfather”

lerfu liste
“letter list” or a “list of letters”

As noted above, CVC-form rafsi cannot appear as the final rafsi in a lujvo, because all lujvo must end with one or two vowels. As a brivla, a lujvo must also contain a consonant cluster within the first five letters – this ensures that they cannot be mistaken for compound cmavo. Of course, all lujvo have at least six letters since they have two or more rafsi, each at least three letters long; hence they cannot be confused with gismu.

When attaching two rafsi together, it may be necessary to insert a hyphen letter. In Lojban, the term “hyphen” always refers to a letter, either the vowel y or one of the consonants r and n. (The letter l can also be a hyphen, but is not used as one in lujvo.)

The y-hyphen is used after a CVC-form rafsi when joining it with the following rafsi could result in an impermissible consonant pair, or when the resulting lujvo could fall apart into two or more words (either cmavo or gismu).

Thus, the tanru

pante tavla ( “protest talk”) cannot produce the lujvo
patta'a, because

tt is not a permissible consonant pair; the lujvo must be patyta'a. Similarly, the tanru

mudri siclu ( “wooden whistle”) cannot form the lujvo
mudsiclu; instead, mudysiclu must be used. (Remember that y is not counted in determining whether the first five letters of a brivla contain a consonant cluster: this is why.)

The y-hyphen is also used to attach a 4-letter rafsi, formed by dropping the final vowel of a gismu, to the following rafsi. (This procedure was shown, but not explained, in Example to Example .)

The lujvo forms zunlyjamfu, zunlyjma, zuljamfu, and zuljma are all legitimate and equivalent forms made from the tanru

zunle jamfu ( “left foot”). Of these, zuljma is the preferred one since it is the shortest; it thus is likely to be the form listed in a Lojban dictionary.

The r-hyphen and its close relative, the n-hyphen, are used in lujvo only after CVV-form rafsi. A hyphen is always required in a two-part lujvo of the form CVV-CVV, since otherwise there would be no consonant cluster.

An r-hyphen or n-hyphen is also required after the CVV-form rafsi of any lujvo of the form CVV-CVC/CV or CVV-CCVCV since it would otherwise fall apart into a CVV-form cmavo and a gismu. In any lujvo with more than two parts, a CVV-form rafsi in the initial position must always be followed by a hyphen. If the hyphen were to be omitted, the supposed lujvo could be broken into smaller words without the hyphen: because the CVV-form rafsi would be interpreted as a cmavo, and the remainder of the word as a valid lujvo that is one rafsi shorter.

An n-hyphen is only used in place of an r-hyphen when the following rafsi begins with r. For example, the tanru

rokci renro ( “rock throw”) cannot be expressed as
ro'ire'o (which breaks up into two cmavo), nor can it be
ro'irre'o (which has an impermissible double consonant); the

n-hyphen is required, and the correct form of the hyphenated lujvo is ro'inre'o. The same lujvo could also be expressed without hyphenation as rokre'o.

There is also a different way of building lujvo, or rather phrases which are grammatically and semantically equivalent to lujvo. You can make a phrase containing any desired words, joining each pair of them with the special cmavo zei. Thus,

bridi zei valsi

is the exact equivalent of brivla (but not necessarily the same as the underlying tanru

bridi valsi, which could have other meanings.) Using zei is the only way to get a cmavo lacking a rafsi, a cmene, or a fu'ivla into a lujvo:

xy. zei kantu
X ray

kulnr,farsi zei lolgai
Farsi floor-cover
Persian rug

na'e zei .a zei na'e zei by. livgyterbilma
non-A, non-B liver-disease
non-A, non-B hepatitis

.cerman. zei jamkarce
Sherman war-car
Sherman tank

Example is particularly noteworthy because the phrase that would be produced by removing the zei s from it doesn't end with a brivla, and in fact is not even grammatical. As written, the example is a tanru with two components, but by adding a zei between by. and livgyterbilma to produce

na'e zei .a zei na'e zei by. zei livgyterbilma

the whole phrase would become a single lujvo. The longer lujvo of Example may be preferable, because its place structure can be built from that of bilma, whereas the place structure of a lujvo without a brivla must be constructed ad hoc.

Note that rafsi may not be used in zei phrases, because they are not words. CVV rafsi look like words (specifically cmavo) but there can be no confusion between the two uses of the same letters, because cmavo appear only as separate words or in compound cmavo (which are really just a notation for writing separate but closely related words as if they were one); rafsi appear only as parts of lujvo.


The use of tanru or lujvo is not always appropriate for very concrete or specific terms (e.g. “brie” or “cobra”), or for jargon words specialized to a narrow field (e.g. “quark”, “integral”, or “iambic pentameter”). These words are in effect names for concepts, and the names were invented by speakers of another language. The vast majority of words referring to plants, animals, foods, and scientific terminology cannot be easily expressed as tanru. They thus must be borrowed (actually “copied”) into Lojban from the original language.

There are four stages of borrowing in Lojban, as words become more and more modified (but shorter and easier to use). Stage 1 is the use of a foreign name quoted with the cmavo la'o (explained in full in Section 18.53):

me la'o ly. spaghetti .ly.

is a predicate with the place structure “x1 is a quantity of spaghetti”.

Stage 2 involves changing the foreign name to a Lojbanized name, as explained in Section 5.7:

me la spagetis.

One of these expedients is often quite sufficient when you need a word quickly in conversation. (This can make it easier to get by when you do not yet have full command of the Lojban vocabulary, provided you are talking to someone who will recognize the borrowing.)

Where a little more universality is desired, the word to be borrowed must be Lojbanized into one of several permitted forms. A rafsi is then usually attached to the beginning of the Lojbanized form, using a hyphen to ensure that the resulting word doesn't fall apart.

The rafsi categorizes or limits the meaning of the fu'ivla; otherwise a word having several different jargon meanings in other languages would require the word-inventor to choose which meaning should be assigned to the fu'ivla, since fu'ivla (like other brivla) are not permitted to have more than one definition. Such a Stage 3 borrowing is the most common kind of fu'ivla.

Finally, Stage 4 fu'ivla do not have any rafsi classifier, and are used where a fu'ivla has become so common or so important that it must be made as short as possible. (See Section 5.15 for a proposal concerning Stage 4 fu'ivla.)

The form of a fu'ivla reliably distinguishes it from both the gismu and the cmavo. Like cultural gismu, fu'ivla are generally based on a word from a single non-Lojban language. The word is “borrowed” (actually “copied”, hence the Lojban tanru

fukpi valsi) from the other language and Lojbanized – the phonemes are converted to their closest Lojban equivalent and modifications are made as necessary to make the word a legitimate Lojban fu'ivla-form word. All fu'ivla:
  • must contain a consonant cluster in the first five letters of the word; if this consonant cluster is at the beginning, it must either be a permissible initial consonant pair, or a longer cluster such that each pair of adjacent consonants in the cluster is a permissible initial consonant pair: spraile is acceptable, but not ktraile or trkaile;
  • must end in one or more vowels;
  • must not be gismu or lujvo, or any combination of cmavo, gismu, and lujvo; furthermore, a fu'ivla with a CV cmavo joined to the front of it must not have the form of a lujvo (the so-called “slinku'i test”, not discussed further in this book);
  • cannot contain y, although they may contain syllabic pronunciations of Lojban consonants;
  • like other brivla, are stressed on the penultimate syllable.

Note that consonant triples or larger clusters that are not at the beginning of a fu'ivla can be quite flexible, as long as all consonant pairs are permissible. There is no need to restrict fu'ivla clusters to permissible initial pairs except at the beginning.

This is a fairly liberal definition and allows quite a lot of possibilities within “fu'ivla space”. Stage 3 fu'ivla can be made easily on the fly, as lujvo can, because the procedure for forming them always guarantees a word that cannot violate any of the rules. Stage 4 fu'ivla require running tests that are not simple to characterize or perform, and should be made only after deliberation and by someone knowledgeable about all the considerations that apply.

Here is a simple and reliable procedure for making a non-Lojban word into a valid Stage 3 fu'ivla:

  • Eliminate all double consonants and silent letters.
  • Convert all sounds to their closest Lojban equivalents. Lojban y, however, may not be used in any fu'ivla.
  • If the last letter is not a vowel, modify the ending so that the word ends in a vowel, either by removing a final consonant or by adding a suggestively chosen final vowel.
  • If the first letter is not a consonant, modify the beginning so that the word begins with a consonant, either by removing an initial vowel or adding a suggestively chosen initial consonant.
  • Prefix the result of steps 1-5 with a 4-letter rafsi that categorizes the fu'ivla into a “topic area”. It is only safe to use a 4-letter rafsi; short rafsi sometimes produce invalid fu'ivla. Hyphenate the rafsi to the rest of the fu'ivla with an

r-hyphen; if that would produce a double r, use an n-hyphen instead; if the rafsi ends in r and the rest of the fu'ivla begins with n (or vice versa), or if the rafsi ends in "r" and the rest of the fu'ivla begins with "tc", "ts", "dj", or "dz" (using "n" would result in a phonotactically impermissible cluster), use an l-hyphen. (This is the only use of l-hyphen in Lojban.)

Alternatively, if a CVC-form short rafsi is available it can be used instead of the long rafsi.

  • Remember that the stress necessarily appears on the penultimate (next-to-the-last) syllable.

In this section, the hyphen is set off with commas in the examples, but these commas are not required in writing, and the hyphen need not be pronounced as a separate syllable.

Here are a few examples:

from English or Italian
prefix long rafsi
prefix short rafsi

where cidj- is the 4-letter rafsi for cidja, the Lojban gismu for “food”, thus categorizing cidjrspageti as a kind of food. The form with the short rafsi happens to work, but such good fortune cannot be relied on: in any event, it means the same thing.

the scientific name of maple trees
add initial consonant and final vowel
prefix rafsi
prefix short rafsi

where tric- and ric- are rafsi for tricu, the gismu for “tree”. Note that by the same principles, “maple sugar” could get the fu'ivla saktrxaceru, or could be represented by the tanru

tricrxaceru sakta. Technically, ricrxaceru and tricrxaceru are distinct fu'ivla, but they would surely be given the same meanings if both happened to be in use.

from French
prefix rafsi

where cirl- represents cirla ( “cheese”).

prefix rafsi

where sinc- represents since ( “snake”).

add final vowel
prefix rafsi

where sask- represents saske ( “science”). Note the extra vowel a added to the end of the word, and the diphthong ua, which never appears in gismu or lujvo, but may appear in fu'ivla.

from Korean
prefix rafsi
prefix rafsi

where ler- represents lerfu ( “letter”). Note the l-hyphen in "lerldjamo", since "lerndjamo" contains the forbidden cluster "ndj".

The use of the prefix helps distinguish among the many possible meanings of the borrowed word, depending on the field. As it happens, spageti and kuarka are valid Stage 4 fu'ivla, but

xaceru looks like a compound cmavo, and
kobra like a gismu.

For another example, “integral” has a specific meaning to a mathematician. But the Lojban fu'ivla integrale, which is a valid Stage 4 fu'ivla, does not convey that mathematical sense to a non-mathematical listener, even one with an English-speaking background; its source – the English word “integral” – has various other specialized meanings in other fields.

Left uncontrolled, integrale almost certainly would eventually come to mean the same collection of loosely related concepts that English associates with “integral”, with only the context to indicate (possibly) that the mathematical term is meant.

The prefix method would render the mathematical concept as cmacrntegrale, if the i of integrale is removed, or something like cmacrnintegrale, if a new consonant is added to the beginning; cmac- is the rafsi for cmaci ( “mathematics”). The architectural sense of “integral” might be conveyed with djinrnintegrale or tarmrnintegrale, where dinju and tarmi mean “building” and “form” respectively.

Here are some fu'ivla representing cultures and related things, shown with more than one rafsi prefix:

in language

in culture

the country

the language

the culture

Note the commas in Example and Example , used because ea is not a valid diphthong in Lojban. Arguably, some form of the native name “Chosen” should have been used instead of the internationally known “Korea”; this is a recurring problem in all borrowings. In general, it is better to use the native name unless using it will severely impede understanding: “Navajo” is far more widely known than “Dine'e”.


Lojbanized names, called cmene, are very much like their counterparts in other languages. They are labels applied to things (or people) to stand for them in descriptions or in direct address. They may convey meaning in themselves, but do not necessarily do so.

Because names are often highly personal and individual, Lojban attempts to allow native language names to be used with a minimum of modification. The requirement that the Lojban speech stream be unambiguously analyzable, however, means that most names must be modified somewhat when they are Lojbanized. Here are a few examples of English names and possible Lojban equivalents:







(Note that syllabic r is skipped in determining the stressed syllable, so Example is stressed on the ka.)



Names may have almost any form, but always end in a consonant, and are followed by a pause. They are penultimately stressed, unless unusual stress is marked with capitalization. A name may have multiple parts, each ending with a consonant and pause, or the parts may be combined into a single word with no pause. For example,

djan. braun.



are both valid Lojbanizations of “John Brown”.

The final arbiter of the correct form of a name is the person doing the naming, although most cultures grant people the right to determine how they want their own name to be spelled and pronounced. The English name “Mary” can thus be Lojbanized as meris., maris., meiris., merix., or even marys.. The last alternative is not pronounced much like its English equivalent, but may be desirable to someone who values spelling over pronunciation. The final consonant need not be an s; there must, however, be some Lojban consonant at the end.

Names are not permitted to have the sequences la, lai, or doi embedded in them, unless the sequence is immediately preceded by a consonant. These minor restrictions are due to the fact that all Lojban cmene embedded in a speech stream will be preceded by one of these words or by a pause. With one of these words embedded, the cmene might break up into valid Lojban words followed by a shorter cmene. However, break-up cannot happen after a consonant, because that would imply that the word before the la, or whatever, ended in a consonant without pause, which is impossible.

For example, the invalid name laplas. would look like the Lojban words

la plas., and

ilanas. would be misunderstood as

.i la nas.. However,
NEderlants. cannot be misheard as
NEder lants., because
NEder with no following pause is not a possible Lojban word.

There are close alternatives to these forbidden sequences that can be used in Lojbanizing names, such as ly, lei, and dai or do'i, that do not cause these problems.

Lojban cmene are identifiable as word forms by the following characteristics:

  • They must end in one or more consonants. There are no rules about how many consonants may appear in a cluster in cmene, provided that each consonant pair (whether standing by itself, or as part of a larger cluster) is a permissible pair.
  • They may contain the letter y as a normal, non-hyphenating vowel. They are the only kind of Lojban word that may contain the two diphthongs iy and uy.
  • They are always followed in speech by a pause after the final consonant, written as ..
  • They may be stressed on any syllable; if this syllable is not the penultimate one, it must be capitalized when writing. Neither names nor words that begin sentences are capitalized in Lojban, so this is the only use of capital letters.

Names meeting these criteria may be invented, Lojbanized from names in other languages, or formed by appending a consonant onto a cmavo, a gismu, a fu'ivla or a lujvo. Some cmene built from Lojban words are:

the One

from the cmavo pa, with rafsi pav, meaning “one”

the Sun

from the gismu solri, meaning “solar”, or actually “pertaining to the Sun”

as a title

from the gismu ralju, meaning “principal”.


from the gismu nobli, with rafsi nol, meaning “noble”.

To Lojbanize a name from the various natural languages, apply the following rules:

  • Eliminate double consonants and silent letters.
  • Add a final s or n (or some other consonant that sounds good) if the name ends in a vowel.
  • Convert all sounds to their closest Lojban equivalents.
  • If possible and acceptable, shift the stress to the penultimate (next-to-the-last) syllable. Use commas and capitalization in written Lojban when it is necessary to preserve non-standard syllabication or stress. Do not capitalize names otherwise.
  • If the name contains an impermissible consonant pair, insert a vowel between the consonants: y is recommended.
  • No cmene may have the syllables la, lai, or doi in them, unless immediately preceded by a consonant. If these combinations are present, they must be converted to something else. Possible substitutions include ly,
ly'i, and dai or

do'i, respectively.

There are some additional rules for Lojbanizing the scientific names (technically known as “Linnaean binomials” after their inventor) which are internationally applied to each species of animal or plant. Where precision is essential, these names need not be Lojbanized, but can be directly inserted into Lojban text using the cmavo la'o, explained in Section 18.53. Using this cmavo makes the already lengthy Latinized names at least four syllables longer, however, and leaves the pronunciation in doubt. The following suggestions, though incomplete, will assist in converting Linnaean binomals to valid Lojban names. They can also help to create fu'ivla based on Linnaean binomials or other words of the international scientific vocabulary. The term “back vowel” in the following list refers to any of the letters a, o, or u; the term “front vowel” correspondingly refers to any of the letters e, i, or y.

  • Change double consonants other than

cc to single consonants.

  • Change

cc before a front vowel to kc, but otherwise to k.

  • Change c before a back vowel and final c to k.
  • Change

ng before a consonant (other than h) and final ng to n.

  • Change x to z initially, but otherwise to


  • Change

pn to n initially.

  • Change final ie and ii to i.
  • Make the following idiosyncratic substitutions:

<tab class=wikitable header=true> aa a ae e ch k ee i eigh ei ew u igh ai oo u ou u ow au ph f q k sc sk w u y i </tab> However, the diphthong substitutions should not be done if the two vowels are in two different syllables.

  • Change “h” between two vowels to ', but otherwise remove it completely. If preservation of the “h” seems essential, change it to x instead.
  • Place ' between any remaining vowel pairs that do not form Lojban diphthongs.

Some further examples of Lojbanized names are: <tab class=wikitable header=true>English “Mary” meris. or meiris. English “Smith” smit. English “Jones” djonz. English “John” djan. or jan. (American) or djon. or jon. (British) English “Alice” .alis. English “Elise” .eLIS. English “Johnson” djansn. English “William” .uiliam. or .uil,iam. English “Brown” braun. English “Charles” tcarlz. French “Charles” carl. French “De Gaulle” dyGOL. German “Heinrich” xainrix. Spanish “Joaquin” xuaKIN. Russian “Svetlana” sfietlanys. Russian “Khrushchev” xrucTCOF. Hindi “Krishna” kricnas. Polish “Lech Walesa” lex. va,uensas. Spanish “Don Quixote” don. kicotes. or modern Spanish: don. kixotes. or Mexican dialect: don. ki'otes. Chinese “Mao Zedong” maudzydyn. Japanese “Fujiko” fudjikos. or fujikos. </tab>

Rules for inserting pauses

Summarized in one place, here are the rules for inserting pauses between Lojban words:

  • Any two words may have a pause between them; it is always illegal to pause in the middle of a word, because that breaks up the word into two words.
  • Every word ending in a consonant must be followed by a pause. Necessarily, all such words are cmene.
  • Every word beginning with a vowel must be preceded by a pause. Such words are either cmavo, fu'ivla, or cmene; all gismu and lujvo begin with consonants.
  • Every cmene must be preceded by a pause, unless the immediately preceding word is one of the cmavo la, lai, la'i, or doi (which is why those strings are forbidden in cmene). However, the situation triggering this rule rarely occurs.
  • If the last syllable of a word bears the stress, and a brivla follows, the two must be separated by a pause, to prevent confusion with the primary stress of the brivla. In this case, the first word must be either a cmavo or a cmene with unusual stress (which already ends with a pause, of course).
  • A cmavo of the form “Cy” must be followed by a pause unless another “Cy”-form cmavo follows.
  • When non-Lojban text is embedded in Lojban, it must be preceded and followed by pauses. (How to embed non-Lojban text is explained in

Section 18.53.)

Considerations for making lujvo

Given a tanru which expresses an idea to be used frequently, it can be turned into a lujvo by following the lujvo-making algorithm which is given in Section 5.10.

In building a lujvo, the first step is to replace each gismu with a rafsi that uniquely represents that gismu. These rafsi are then attached together by fixed rules that allow the resulting compound to be recognized as a single word and to be analyzed in only one way.

There are three other complications; only one is serious.

The first is that there is usually more than one rafsi that can be used for each gismu. The one to be used is simply whichever one sounds or looks best to the speaker or writer. There are usually many valid combinations of possible rafsi. They all are equally valid, and all of them mean exactly the same thing. (The scoring algorithm given in Section 5.11 is used to choose the standard form of the lujvo – the version which would be entered into a dictionary.)

The second complication is the serious one. Remember that a tanru is ambiguous – it has several possible meanings. A lujvo, or at least one that would be put into the dictionary, has just a single meaning. Like a gismu, a lujvo is a predicate which encompasses one area of the semantic universe, with one set of places. Hopefully the meaning chosen is the most useful of the possible semantic spaces. A possible source of linguistic drift in Lojban is that as Lojbanic society evolves, the concept that seems the most useful one may change.

You must also be aware of the possibility of some prior meaning of a new lujvo, especially if you are writing for posterity. If a lujvo is invented which involves the same tanru as one that is in the dictionary, and is assigned a different meaning (or even just a different place structure), linguistic drift results. This isn't necessarily bad. Every natural language does it. But in communication, when you use a meaning different from the dictionary definition, someone else may use the dictionary and therefore misunderstand you. You can use the cmavo za'e (explained in Section 18.54) before a newly coined lujvo to indicate that it may have a non-dictionary meaning.

The essential nature of human communication is that if the listener understands, then all is well. Let this be the ultimate guideline for choosing meanings and place structures for invented lujvo.

The third complication is also simple, but tends to scare new Lojbanists with its implications. It is based on Zipf's Law, which says that the length of words is inversely proportional to their usage. The shortest words are those which are used more; the longest ones are used less. Conversely, commonly used concepts will be tend to be abbreviated. In English, we have abbreviations and acronyms and jargon, all of which represent complex ideas that are used often by small groups of people, so they shortened them to convey more information more rapidly.

Therefore, given a complicated tanru with grouping markers, abstraction markers, and other cmavo in it to make it syntactically unambiguous, the psychological basis of Zipf's Law may compel the lujvo-maker to drop some of the cmavo to make a shorter (technically incorrect) tanru, and then use that tanru to make the lujvo.

This doesn't lead to ambiguity, as it might seem to. A given lujvo still has exactly one meaning and place structure. It is just that more than one tanru is competing for the same lujvo. But more than one meaning for the tanru was already competing for the “right” to define the meaning of the lujvo. Someone has to use judgment in deciding which one meaning is to be chosen over the others.

If the lujvo made by a shorter form of tanru is in use, or is likely to be useful for another meaning, the decider then retains one or more of the cmavo, preferably ones that set this meaning apart from the shorter form meaning that is used or anticipated. As a rule, therefore, the shorter lujvo will be used for a more general concept, possibly even instead of a more frequent word. If both words are needed, the simpler one should be shorter. It is easier to add a cmavo to clarify the meaning of the more complex term than it is to find a good alternate tanru for the simpler term.

And of course, we have to consider the listener. On hearing an unknown word, the listener will decompose it and get a tanru that makes no sense or the wrong sense for the context. If the listener realizes that the grouping operators may have been dropped out, he or she may try alternate groupings, or try inserting an abstraction operator if that seems plausible. (The grouping of tanru is explained in Chapter 6; abstraction is explained in Chapter 16.) Plausibility is the key to learning new ideas and to evaluating unfamiliar lujvo.

The lujvo-making algorithm

The following is the current algorithm for generating Lojban lujvo given a known tanru and a complete list of gismu and their assigned rafsi. The algorithm was designed by Bob LeChevalier and Dr. James Cooke Brown for computer program implementation. It was modified in 1989 with the assistance of Nora LeChevalier, who detected a flaw in the original “tosmabru test”.

Given a tanru that is to be made into a lujvo:

  • Choose a 3-letter or 4-letter rafsi for each of the gismu and cmavo in the tanru except the last.
  • Choose a 3-letter (CVV-form or CCV-form) or 5-letter rafsi for the final gismu in the tanru.
  • Join the resulting string of rafsi, initially without hyphens.
  • Add hyphen letters where necessary. It is illegal to add a hyphen at a place that is not required by this algorithm. Right-to-left tests are recommended, for reasons discussed below.
  • If there are more than two words in the tanru, put an

r-hyphen (or an n-hyphen) after the first rafsi if it is CVV-form. If there are exactly two words, then put an r-hyphen (or an n-hyphen) between the two rafsi if the first rafsi is CVV-form, unless the second rafsi is CCV-form (for example,

saicli requires no hyphen). Use an

r-hyphen unless the letter after the hyphen is r, in which case use an n-hyphen. Never use an n-hyphen unless it is required.

  • Put a

y-hyphen between the consonants of any impermissible consonant pair. This will always appear between rafsi.

  • Put a

y-hyphen after any 4-letter rafsi form.

  • Test all forms with one or more initial CVC-form rafsi – with the pattern “CVC ... CVC + X” – for “tosmabru failure”. X must either be a CVCCV long rafsi that happens to have a permissible initial pair as the consonant cluster, or is something which has caused a

y-hyphen to be installed between the previous CVC and itself by one of the above rules.

The test is as follows:

  • Examine all the C/C consonant pairs up to the first y-hyphen, or up to the end of the word in case there are no y-hyphens.

These consonant pairs are called "joints”.

  • If all of those joints are permissible initials, then the trial word will break up into a cmavo and a shorter brivla. If not, the word will not break up, and no further hyphens are needed.
  • Install a y-hyphen at the first such joint.

Note that the “tosmabru test” implies that the algorithm will be more efficient if rafsi junctures are tested for required hyphens from right to left, instead of from left to right; when the test is required, it cannot be completed until hyphenation to the right has been determined.

The lujvo scoring algorithm

This algorithm was devised by Bob and Nora LeChevalier in 1989. It is not the only possible algorithm, but it usually gives a choice that people find preferable. The algorithm may be changed in the future. The lowest-scoring variant will usually be the dictionary form of the lujvo. (In previous versions, it was the highest-scoring variant.)

  • Count the total number of letters, including hyphens and apostrophes; call it


  • Count the number of apostrophes; call it


  • Count the number of y-, r-, and

n-hyphens; call it


  • For each rafsi, find the value in the following table. Sum this value over all rafsi; call it

R: <tab class=wikitable header=true>CVC/CV (final) (-sarji) 1 CVC/C (-sarj-) 2 CCVCV (final) (-zbasu) 3 CCVC (-zbas-) 4 CVC (-nun-) 5 CVV with an apostrophe (-ta'u-) 6 CCV (-zba-) 7 CVV with no apostrophe (-sai-) 8 </tab>

  • Count the number of vowels, not including y; call it


The score is then: (1000 * L) - (500 * A) + (100 * H) - (10 * R) - V In case of ties, there is no preference. This should be rare. Note that the algorithm essentially encodes a hierarchy of priorities: short words are preferred (counting apostrophes as half a letter), then words with fewer hyphens, words with more pleasing rafsi (this judgment is subjective), and finally words with more vowels are chosen. Each decision principle is applied in turn if the ones before it have failed to choose; it is possible that a lower-ranked principle might dominate a higher-ranked one if it is ten times better than the alternative.

Here are some lujvo with their scores (not necessarily the lowest scoring forms for these lujvo, nor even necessarily sensible lujvo):


zba + sai {{{1}}}


nun + y + nau {{{1}}}


sai + r + zba + ta'u {{{1}}}


zba + zbas + y + sarji {{{1}}}

lujvo-making examples

This section contains examples of making and scoring lujvo. First, we will start with the tanru

gerku zdani ( “dog house”) and construct a lujvo meaning “doghouse”, that is, a house where a dog lives. We will use a brute-force application of the algorithm in Section 5.11, using every possible rafsi.

The rafsi for gerku are:

  • -ger-,
  • -ge'u-,
  • -gerk-,
  • -gerku

The rafsi for zdani are:

  • -zda-,
  • -zdan-,
  • -zdani.

Step 1 of the algorithm directs us to use -ger-, -ge'u- and -gerk- as possible rafsi for gerku; Step 2 directs us to use -zda- and -zdani as possible rafsi for zdani. The six possible forms of the lujvo are then:

  • ger-zda
  • ger-zdani
  • ge'u-zda
  • ge'u-zdani
  • gerk-zda
  • gerk-zdani

We must then insert appropriate hyphens in each case. The first two forms need no hyphenation: ge cannot fall off the front, because the following word would begin with rz, which is not a permissible initial consonant pair. So the lujvo forms are gerzda and gerzdani.

The third form, ge'u-zda, needs no hyphen, because even though the first rafsi is CVV, the second one is CCV, so there is a consonant cluster in the first five letters. So ge'uzda is this form of the lujvo.

The fourth form,

ge'u-zdani, however, requires an

r-hyphen; otherwise, the ge'u- part would fall off as a cmavo. So this form of the lujvo is ge'urzdani.

The last two forms require y-hyphens, as all 4-letter rafsi do, and so are gerkyzda and gerkyzdani respectively.

The scoring algorithm is heavily weighted in favor of short lujvo, so we might expect that gerzda would win. Its L score is 6, its A score is 0, its H score is 0, its R score is 12, and its V score is 3, for a final score of 5878. The other forms have scores of 7917, 6367, 9506, 8008, and 10047 respectively. Consequently, this lujvo would probably appear in the dictionary in the form gerzda.

For the next example, we will use the tanru

bloti klesi ( “boat class”) presumably referring to the category (rowboat, motorboat, cruise liner) into which a boat falls. We will omit the long rafsi from the process, since lujvo containing long rafsi are almost never preferred by the scoring algorithm when there are short rafsi available.

The rafsi for bloti are -lot-, -blo-, and -lo'i-; for klesi they are -kle- and -lei-. Both these gismu are among the handful which have both CVV-form and CCV-form rafsi, so there is an unusual number of possibilities available for a two-part tanru:

  • lotkle
  • blokle
  • lo'ikle
  • lotlei
  • blolei
  • lo'irlei

Only lo'irlei requires hyphenation (to avoid confusion with the cmavo sequence lo'i lei). All six forms are valid versions of the lujvo, as are the six further forms using long rafsi; however, the scoring algorithm produces the following results:

lotkle 5878 blokle 5858 lo'ikle 6367 lotlei 5867 blolei 5847 lo'irlei 7456

So the form blolei is preferred, but only by a tiny margin over blokle; "lotlei" and "lotkle" are only slightly worse; lo'ikle suffers because of its apostrophe, and lo'irlei because of having both apostrophe and hyphen.

Our third example will result in forming both a lujvo and a name from the tanru

logji bangu girzu, or “logical-language group” in English. ( “The Logical Language Group” is the name of the publisher of this book and the organization for the promotion of Lojban.)

The available rafsi are -loj- and -logj-; -ban-, -bau-, and -bang-; and -gri- and -girzu, and (for name purposes only) -gir- and -girz-. The resulting 12 lujvo possibilities are:

  • loj-ban-gri
  • loj-bau-gri
  • loj-bang-gri
  • logj-ban-gri
  • logj-bau-gri
  • logj-bang-gri
  • loj-ban-girzu
  • loj-bau-girzu
  • loj-bang-girzu
  • logj-ban-girzu
  • logj-bau-girzu
  • logj-bang-girzu

and the 12 name possibilities are:

  • loj-ban-gir
  • loj-bau-gir
  • loj-bang-gir
  • logj-ban-gir
  • logj-bau-gir
  • logj-bang-gir
  • loj-ban-girz
  • loj-bau-girz
  • loj-bang-girz
  • logj-ban-girz
  • logj-bau-girz
  • logj-bang-girz

After hyphenation, we have:

  • lojbangri
  • lojbaugri
  • lojbangygri
  • logjybangri
  • logjybaugri
  • logjybangygri
  • lojbangirzu
  • lojbaugirzu
  • lojbangygirzu
  • logjybangirzu
  • logjybaugirzu
  • logjybangygirzu
  • lojbangir
  • lojbaugir
  • lojbangygir
  • logjybangir
  • logjybaugir
  • logjybangygir
  • lojbangirz
  • lojbaugirz
  • lojbangygirz
  • logjybangirz
  • logjybaugirz
  • logjybangygirz

The only fully reduced lujvo forms are lojbangri and lojbaugri, of which the latter has a slightly lower score: 8827 versus 8796, respectively. However, for the name of the organization, we chose to make sure the name of the language was embedded in it, and to use the clearer long-form rafsi for girzu, producing lojbangirz.

Finally, here is a four-part lujvo with a cmavo in it, based on the tanru

nakni ke cinse ctuca or “male (sexual teacher)”. The

ke cmavo ensures the interpretation “teacher of sexuality who is male”, rather than “teacher of male sexuality”. Here are the possible forms of the lujvo, both before and after hyphenation:

  • nak-kem-cin-ctu
  • nakykemcinctu
  • nak-kem-cin-ctuca
  • nakykemcinctuca
  • nak-kem-cins-ctu
  • nakykemcinsyctu
  • nak-kem-cins-ctuca
  • nakykemcinsyctuca
  • nakn-kem-cin-ctu
  • naknykemcinctu
  • nakn-kem-cin-ctuca
  • naknykemcinctuca
  • nakn-kem-cins-ctu
  • naknykemcinsyctu
  • nakn-kem-cins-ctuca
  • naknykemcinsyctuca

Of these forms, nakykemcinctu is the shortest and is preferred by the scoring algorithm. On the whole, however, it might be better to just make a lujvo for

cinse ctuca (which would be cinctu) since the sex of the teacher is rarely important. If there was a reason to specify “male”, then the simpler tanru
nakni cinctu ( “male sexual-teacher”) would be appropriate. This tanru is actually shorter than the four-part lujvo, since the ke required for grouping need not be expressed.

The gismu creation algorithm

The gismu were created through the following process:

  • At least one word was found in each of the six source languages (Chinese, English, Hindi, Spanish, Russian, Arabic) corresponding to the proposed gismu. This word was rendered into Lojban phonetics rather liberally: consonant clusters consisting of a stop and the corresponding fricative were simplified to just the fricative (

tc became c, dj became j) and non-Lojban vowels were mapped onto Lojban ones. Furthermore, morphological endings were dropped. The same mapping rules were applied to all six languages for the sake of consistency.

  • All possible gismu forms were matched against the six source-language forms. The matches were scored as follows:
  • If three or more letters were the same in the proposed gismu and the source-language word, and appeared in the same order, the score was equal to the number of letters that were the same. Intervening letters, if any, did not matter.
  • If exactly two letters were the same in the proposed gismu and the source-language word, and either the two letters were consecutive in both words, or were separated by a single letter in both words, the score was 2. Letters in reversed order got no score.
  • Otherwise, the score was 0.
  • The scores were divided by the length of the source-language word in its Lojbanized form, and then multiplied by a weighting value specific to each language, reflecting the proportional number of first-language and second-language speakers of the language. (Second-language speakers were reckoned at half their actual numbers.) The weights were chosen to sum to 1.00. The sum of the weighted scores was the total score for the proposed gismu form.
  • Any gismu forms that conflicted with existing gismu were removed. Obviously, being identical with an existing gismu constitutes a conflict. In addition, a proposed gismu that was identical to an existing gismu except for the final vowel was considered a conflict, since two such gismu would have identical 4-letter rafsi.

More subtly: If the proposed gismu was identical to an existing gismu except for a single consonant, and the consonant was "too similar” based on the following table, then the proposed gismu was rejected. <tab class=wikitable header=true>proposed gismu existing gismub p, vc j, sd tf p, vg k, xj c, zk g, xl rm nn mp b, fr ls c, zt dv b, fx g, kz j, s </tab> See Section 5.3 for an example.

  • The gismu form with the highest score usually became the actual gismu. Sometimes a lower-scoring form was used to provide a better rafsi. A few gismu were changed in error as a result of transcription blunders (for example, the gismu gismu should have been gicmu, but it's too late to fix it now).

The language weights used to make most of the gismu were as follows: <tab class=wikitable header=true>Chinese 0.36 English 0.21 Hindi 0.16 Spanish 0.11 Russian 0.09 Arabic 0.07 </tab> reflecting 1985 number-of-speakers data. A few gismu were made much later using updated weights: <tab class=wikitable header=true>Chinese 0.347 Hindi 0.196 English 0.160 Spanish 0.123 Russian 0.089 Arabic 0.085 </tab> (English and Hindi switched places due to demographic changes.)

Note that the stressed vowel of the gismu was considered sufficiently distinctive that two or more gismu may differ only in this vowel; as an extreme example, bradi, bredi, bridi, and brodi (but fortunately not brudi) are all existing gismu.

Cultural and other non-algorithmic gismu

The following gismu were not made by the gismu creation algorithm. They are, in effect, coined words similar to fu'ivla. They are exceptions to the otherwise mandatory gismu creation algorithm where there was sufficient justification for such exceptions. Except for the small metric prefixes and the assignable predicates beginning with brod-, they all end in the letter o, which is otherwise a rare letter in Lojban gismu.

The following gismu represent concepts that are sufficiently unique to Lojban that they were either coined from combining forms of other gismu, or else made up out of whole cloth. These gismu are thus conceptually similar to lujvo even though they are only five letters long; however, unlike lujvo, they have rafsi assigned to them for use in building more complex lujvo. Assigning gismu to these concepts helps to keep the resulting lujvo reasonably short.

1st assignable predicate
2nd assignable predicate
3rd assignable predicate
4th assignable predicate
5th assignable predicate
structure word (from cmalu valsi)
Lojbanic (from logji bangu)
compound word (from pluja valsi)
Mathematical EXpression

It is important to understand that even though cmavo, lojbo, and lujvo were made up from parts of other gismu, they are now full-fledged gismu used in exactly the same way as all other gismu, both in grammar and in word formation.

The following three groups of gismu represent concepts drawn from the international language of science and mathematics. They are used for concepts that are represented in most languages by a root which is recognized internationally.

Small metric prefixes (values less than 1): <tab class=wikitable header=true>decti .1 decicenti .01 centimilti .001 millimikri 10-6 micronanvi 10-9 nanopicti 10-12 picofemti 10-15 femtoxatsi 10-18 attozepti 10-21 zeptogocti 10-24 yocto </tab> Large metric prefixes (values greater than 1): <tab class=wikitable header=true>dekto 10 dekaxecto 100 hectokilto 1000 kilomegdo 106 megagigdo 109 gigaterto 1012 terapetso 1015 petaxexso 1018 exazetro 1021 zettagotro 1024 yotta </tab> Other scientific or mathematical terms:


The gismu sinso and tanjo were only made non-algorithmically because they were identical (having been borrowed from a common source) in all the dictionaries that had translations. The other terms in this group are units in the international metric system; some metric units, however, were made by the ordinary process (usually because they are different in Chinese).

Finally, there are the cultural gismu, which are also borrowed, but by modifying a word from one particular language, instead of using the multi-lingual gismu creation algorithm. Cultural gismu are used for words that have local importance to a particular culture; other cultures or languages may have no word for the concept at all, or may borrow the word from its home culture, just as Lojban does. In such a case, the gismu algorithm, which uses weighted averages, doesn't accurately represent the frequency of usage of the individual concept. Cultural gismu are not even required to be based on the six major languages.

The six Lojban source languages:

Chinese (from "Zhong 1 guo 2")

Seven other widely spoken languages that were on the list of candidates for gismu-making, but weren't used:

Bahasa Melayu/Bahasa Indonesia
Japanese (from “Nippon”)
German (from "Deutsch")
French (from "Français")

(Urdu and Hindi began as the same language with different writing systems, but have now become somewhat different, principally in borrowed vocabulary. Urdu-speakers were counted along with Hindi-speakers when weights were assigned for gismu-making purposes.)

Countries with a large number of speakers of any of the above languages (where the meaning of “large” is dependent on the specific language): <tab class=wikitable header=true> English:merko Americanbrito Britishskoto Scottishsralo Australiankadno Canadian </tab> <tab class=wikitable header=true> Spanish:gento Argentinianmexno Mexican </tab> <tab class=wikitable header=true> Russian:softo Soviet/USSRvukro Ukrainian </tab> <tab class=wikitable header=true> Arabic:filso Palestinianjerxo Algerianjordo Jordanianlibjo Libyanlubno Lebanesemisro Egyptian (from "Mizraim")morko Moroccanrakso Iraqisadjo Saudisirxo Syrian </tab> <tab class=wikitable header=true> Bahasa Melayu/Bahasa Indonesia:bindo Indonesianmeljo Malaysian </tab> <tab class=wikitable header=true> Portuguese:brazo Brazilian </tab> <tab class=wikitable header=true> Urdu:kisto Pakistani </tab>

The continents (and oceanic regions) of the Earth:

North American (from berti merko)
Antarctican (from cadzu cipni)
South American (from "Quechua")

A few smaller but historically important cultures:

Greek (from "Hellas")

Major world religions:


A few terms that cover multiple groups of the above:

Jehovist (Judeo-Christian-Moslem)
Hispanic (New World Spanish)

rafsi fu'ivla: a proposal

The list of cultures represented by gismu, given in Section 5.14, is unavoidably controversial. Much time has been spent debating whether this or that culture “deserves a gismu” or “must languish in fu'ivla space”. To help defuse this argument, a last-minute proposal was made when this book was already substantially complete. I have added it here with experimental status: it is not yet a standard part of Lojban, since all its implications have not been tested in open debate, and it affects a part of the language (lujvo-making) that has long been stable, but is known to be fragile in the face of small changes. (Many attempts were made to add general mechanisms for making lujvo that contained fu'ivla, but all failed on obvious or obscure counterexamples; finally the general zei mechanism was devised instead.)

The first part of the proposal is uncontroversial and involves no change to the language mechanisms. All valid Type 4 fu'ivla of the form CCVVCV would be reserved for cultural brivla analogous to those described in Section 5.14. For example,


is of the appropriate form, and passes all tests required of a Stage 4 fu'ivla. No two fu'ivla of this form would be allowed to coexist if they differed only in the final vowel; this rule was applied to gismu, but does not apply to other fu'ivla or to lujvo.

The second, and fully experimental, part of the proposal is to allow rafsi to be formed from these cultural fu'ivla by removing the final vowel and treating the result as a 4-letter rafsi (although it would contain five letters, not four). These rafsi could then be used on a par with all other rafsi in forming lujvo. The tanru

tci'ile ke canre tutra
Chilean type-of
sand territory
Chilean desert

could be represented by the lujvo


which is an illegal word in standard Lojban, but a valid lujvo under this proposal. There would be no short rafsi or 5-letter rafsi assigned to any fu'ivla, so no fu'ivla could appear as the last element of a lujvo.

The cultural fu'ivla introduced under this proposal are called

rafsi fu'ivla, since they are distinguished from other Type 4 fu'ivla by the property of having rafsi. If this proposal is workable and introduces no problems into Lojban morphology, it might become standard for all Type 4 fu'ivla, including those made for plants, animals, foodstuffs, and other things.

The structure of main verb (selbri)

Lojban content words: brivla

At the center, logically and often physically, of every Lojban bridi is one or more words which constitute the selbri. A bridi expresses a relationship between things: the selbri specifies which relationship is referred to. The difference between:

do mamta mi
You are-a-mother-of me
You are my mother


do patfu mi
You are-a-father-of me.
You are my father.

lies in the different selbri.

The simplest kind of selbri is a single Lojban content word: a brivla. There are three different varieties of brivla: those which are built into the language (the gismu), those which are derived from combinations of the gismu (the lujvo), and those which are taken (usually in a modified form) from other languages (the fu'ivla). In addition, there are a few cmavo that can act like brivla; these are mentioned in Section 6.8, and discussed in full in Chapter 10.

For the purposes of this chapter, however, all brivla are alike. For example,

ta bloti
That is-a-boat.
That is a boat.
ta brablo
That is-a-large-boat.
That is a ship.
ta blotrskunri
That is-a-(boat)-schooner.
That is a schooner.

illustrate the three types of brivla (gismu, lujvo, and fu'ivla respectively), but in each case the selbri is composed of a single word whose meaning can be learned independent of its origins.

The remainder of this chapter will mostly use gismu as example brivla, because they are short. However, it is important to keep in mind that wherever a gismu appears, it could be replaced by any other kind of brivla.

Simple tanru

Beyond the single brivla, a selbri may consist of two brivla placed together. When a selbri is built in this way from more than one brivla, it is called a tanru, a word with no single English equivalent. The nearest analogue to tanru in English are combinations of two nouns such as “lemon tree”. There is no way to tell just by looking at the phrase “lemon tree” exactly what it refers to, even if you know the meanings of “lemon” and “tree” by themselves. As English-speakers, we must simply know that it refers to “a tree which bears lemons as fruits”. A person who didn't know English very well might think of it as analogous to “brown tree” and wonder, “What kind of tree is lemon-colored?”

In Lojban, tanru are also used for the same purposes as English adjective-noun combinations like “big boy” and adverb-verb combinations like “quickly run”. This is a consequence of Lojban not having any such categories as “noun”, “verb”, “adjective”, or “adverb”. English words belonging to any of these categories are translated by simple brivla in Lojban. Here are some examples of tanru:

tu pelnimre tricu
That-yonder is-a-(lemon tree).
That is a lemon tree.
la djan. barda nanla
That-named John is-a-big boy.
John is a big boy.
mi sutra bajra
I quick run
I quickly run./I run quickly.

Note that pelnimre is a lujvo for “lemon”; it is derived from the gismu pelxu, yellow, and nimre, citrus. Note also that sutra can mean “fast/quick” or “quickly” depending on its use:

mi sutra
I am-fast/quick

shows sutra used to translate an adjective, whereas in Example it is translating an adverb. (Another correct translation of Example , however, would be “I am a quick runner”.)

There are special Lojban terms for the two components of a tanru, derived from the place structure of the word tanru. The first component is called the seltau, and the second component is called the tertau.

The most important rule for use in interpreting tanru is that the tertau carries the primary meaning. A

pelnimre tricu is primarily a tree, and only secondarily is it connected with lemons in some way. For this reason, an alternative translation of Example would be:

That is a lemon type of tree.

This “type of” relationship between the components of a tanru is fundamental to the tanru concept.

We may also say that the seltau modifies the meaning of the tertau:

That is a tree which is lemon-ish (in the way appropriate to trees)

would be another possible translation of Example . In the same way, a more explicit translation of Example might be:

John is a boy who is big in the way that boys are big.

This “way that boys are big” would be quite different from the way in which elephants are big; big-for-a-boy is small-for-an-elephant.

All tanru are ambiguous semantically. Possible translations of:

ta klama jubme
That is-a-goer type-of-table.


  • That is a table which goes (a wheeled table, perhaps).
  • That is a table owned by one who goes.
  • That is a table used by those who go (a sports doctor's table?).
  • That is a table when it goes (otherwise it is a chair?).

In each case the object referred to is a “goer type of table”, but the ambiguous “type of” relationship can mean one of many things. A speaker who uses tanru (and pragmatically all speakers must) takes the risk of being misunderstood. Using tanru is convenient because they are short and expressive; the circumlocution required to squeeze out all ambiguity can require too much effort.

No general theory covering the meaning of all possible tanru exists; probably no such theory can exist. However, some regularities obviously do exist:

do barda prenu
You are-a-large person.
do cmalu prenu
You are-a-small person.

are parallel tanru, in the sense that the relationship between barda and prenu is the same as that between cmalu and prenu. Section 6.13 and Section 6.14 contain a partial listing of some types of tanru, with examples.

Three-part tanru grouping with bo

The following cmavo is discussed in this section:


Consider the English sentence:

That's a little girls' school.

What does it mean? Two possible readings are:

That's a little school for girls.

That's a school for little girls.

This ambiguity is quite different from the simple tanru ambiguity described in Section 6.1. We understand that “girls' school” means “a school where girls are the students”, and not “a school where girls are the teachers” or “a school which is a girl” (!). Likewise, we understand that “little girl” means “girl who is small”. This is an ambiguity of grouping. Is “girls' school” to be taken as a unit, with “little” specifying the type of girls' school? Or is “little girl” to be taken as a unit, specifying the type of school? In English speech, different tones of voice, or exaggerated speech rhythm showing the grouping, are used to make the distinction; English writing usually leaves it unrepresented.

Lojban makes no use of tones of voice for any purpose; explicit words are used to do the work. The cmavo bo (which belongs to selma'o BO) may be placed between the two brivla which are most closely associated. Therefore, a Lojban translation of Example would be:

ta cmalu nixli bo ckule
That is-a-small girl [] school.Example might be translated:
ta cmalu bo nixli ckule
That is-a-small [] girl school.

The bo is represented in the literal translation by a hyphen because in written English a hyphen is sometimes used for the same purpose: “a big dog-catcher” would be quite different from a “big-dog catcher” (presumably someone who catches only big dogs).

Analysis of Example and Example reveals a tanru nested within a tanru. In Example , the main tanru has a seltau of cmalu and a tertau of

nixli bo ckule; the tertau is itself a tanru with nixli as the seltau and ckule as the tertau. In Example , on the other hand, the seltau is
cmalu bo nixli (itself a tanru), whereas the tertau is ckule.

This structure of tanru nested within tanru forms the basis for all the more complex types of selbri that will be explained below.

What about Example ? What does it mean?

ta cmalu nixli ckule
That is-a-small girl school.

The rules of Lojban do not leave this sentence ambiguous, as the rules of English do with Example . The choice made by the language designers is to say that Example means the same as Example . This is true no matter what three brivla are used: the leftmost two are always grouped together. This rule is called the “left-grouping rule”. Left-grouping in seemingly ambiguous structures is quite common – though not universal – in other contexts in Lojban.

Another way to express the English meaning of Example and Example , using parentheses to mark grouping, is:

ta cmalu [] nixli bo ckule
That is-a-small type-of (girl type-of school).
ta cmalu bo nixli [] ckule
That is-a-(small type-of girl) type-of school.

Because “type-of” is implicit in the Lojban tanru form, it has no Lojban equivalent.

Note: It is perfectly legal, though pointless, to insert bo into a simple tanru:

ta klama bo jubme
That is-a-goer [] table.

is a legal Lojban bridi that means exactly the same thing as Example , and is ambiguous in exactly the same ways. The cmavo bo serves only to resolve grouping ambiguity: it says nothing about the more basic ambiguity present in all tanru.

Complex tanru grouping

If one element of a tanru can be another tanru, why not both elements?

do mutce bo barda gerku bo kavbu
You are-a-(very type-of large) (dog type-of capturer).
You are a very large dog-catcher.

In Example , the selbri is a tanru with seltau

mutce bo barda and tertau
gerku bo kavbu. It is worth emphasizing once again that this tanru has the same fundamental ambiguity as all other Lojban tanru: the sense in which the “dog type-of capturer” is said to be “very type-of large” is not precisely specified. Presumably it is his body which is large, but theoretically it could be one of his other properties.

We will now justify the title of this chapter by exploring the ramifications of the phrase “pretty little girls' school”, an expansion of the tanru used in Section 6.2 to four brivla. (Although this example has been used in the Loglan Project almost since the beginning – it first appeared in Quine's book Word and Object (1960) – it is actually a mediocre example because of the ambiguity of English “pretty”; it can mean “beautiful”, the sense intended here, or it can mean “very”. Lojban melbi is not subject to this ambiguity: it means only “beautiful”.)

Here are four ways to group this phrase:

ta melbi cmalu nixli ckule
That is-a-((pretty type-of little) type-of girl) type-of school.
That is a school for girls who are beautifully small.
ta melbi cmalu nixli bo ckule
That is-a-(pretty type-of little) (girl type-of school).
That is a girls' school which is beautifully small.
ta melbi cmalu bo nixli ckule
That is-a-(pretty type-of (little type-of girl)) type-of school.
That is a school for small girls who are beautiful.
ta melbi cmalu bo nixli bo ckule
That is-a-pretty type-of (little type-of (girl type-of school)).
That is a small school for girls which is beautiful.

Example uses a construction which has not been seen before:

cmalu bo nixli bo ckule, with two consecutive uses of bo between brivla. The rule for multiple bo constructions is the opposite of the rule when no bo is present at all: the last two are grouped together. Not surprisingly, this is called the “right-grouping rule”, and it is associated with every use of

bo in the language. Therefore,

ta cmalu bo nixli bo ckule
That is-a-little type-of (girl type-of school).

means the same as Example , not Example . This rule may seem peculiar at first, but one of its consequences is that bo is never necessary between the first two elements of any of the complex tanru presented so far: all of Example through Example could have bo inserted between melbi and cmalu with no change in meaning.

Complex tanru with ke and ke'e

The following cmavo are discussed in this section:


There is, in fact, a fifth grouping of “pretty little girls' school” that cannot be expressed with the resources explained so far. To handle it, we must introduce the grouping parentheses cmavo, ke and ke'e (belonging to selma'o KE and KEhE respectively). Any portion of a selbri sandwiched between these two cmavo is taken to be a single tanru component, independently of what is adjacent to it. Thus, Example can be rewritten in any of the following ways:

ta ke melbi cmalu ke'e nixli ckule
That is-a-( pretty little ) girl school.
ta ke ke melbi cmalu ke'e nixli ke'e ckule
That is-a-( ( pretty little ) girl ) school.
ta ke ke ke melbi cmalu ke'e nixli ke'e ckule ke'e
That is-a-( ( ( pretty little ) girl ) school ).

Even more versions could be created simply by placing any number of ke cmavo at the beginning of the selbri, and a like number of ke'e cmavo at its end. Obviously, all of these are a waste of breath once the left-grouping rule has been grasped. However, the following is equivalent to Example and may be easier to understand:

ta melbi ke cmalu nixli ke'e ckule
That is-a-( pretty type-of ( little type-of girl ) ) type-of school.

Likewise, a ke and ke'e version of Example would be:

ta melbi cmalu ke nixli ckule [ke'e]
That is-a-(pretty type-of little) ( girl type-of school ).

The final ke'e is given in square brackets here to indicate that it can be elided. It is always possible to elide ke'e at the end of the selbri, making Example as terse as Example .

Now how about that fifth grouping? It is

ta melbi ke cmalu nixli ckule [ke'e]
That is-a-pretty type-of ( ( little type-of girl ) type-of school ).
That is a beautiful school for small girls.

Example is distinctly different in meaning from any of Examples 4.2 through 4.5. Note that within the keke'e parentheses, the left-grouping rule is applied to

cmalu nixli ckule.

It is perfectly all right to mix bo and keke'e in a single selbri. For instance, Example , which in pure keke'e form is

ta melbi ke cmalu ke nixli ckule [ke'e] [ke'e]
That is-a-pretty type-of ( little type-of ( girl type-of school ) ).

can equivalently be expressed as:

ta melbi ke cmalu nixli bo ckule [ke'e]
That is-a-pretty type-of ( little type-of ( girl type-of school ) ).

and in many other different forms as well.

Logical connection within tanru

The following cmavo are discussed in this section:


Consider the English phrase “big red dog”. How shall this be rendered as a Lojban tanru? The naive attempt:

barda xunre gerku
(big type-of red) type-of dog

will not do, as it means a dog whose redness is big, in whatever way redness might be described as “big”. Nor is

barda xunre bo gerku
big type-of (red type-of dog)

much better. After all, the straightforward understanding of the English phrase is that the dog is big as compared with other dogs, not merely as compared with other red dogs. In fact, the bigness and redness are independent properties of the dog, and only obscure rules of English adjective ordering prevent us from saying “red big dog”.

The Lojban approach to this problem is to introduce the cmavo je, which is one of the many equivalents of English “and”. A big red dog is one that is both big and red, and we can say:

barda je xunre gerku
(big and red) type-of dog

Of course,

xunre je barda gerku
(red and big) type-of dog

is equally satisfactory and means the same thing. As these examples indicate, joining two brivla with je makes them a unit for tanru purposes. However, explicit grouping with bo or keke'e associates brivla more closely than je does:

barda je pelxu bo xunre gerku
barda je ke pelxu xunre ke'e gerku
(big and (yellow type-of red)) dog
big yellowish-red dog

With no grouping indicators, we get:

barda je pelxu xunre gerku
((big and yellow) type-of red) type-of dog
biggish- and yellowish-red dog

which again raises the question of Example : what does “biggish-red” mean?

Unlike bo and keke'e, je is useful as well as merely legal within simple tanru. It may be used to partly resolve the ambiguity of simple tanru:

ta blanu je zdani
that is-blue and is-a-house

definitely refers to something which is both blue and is a house, and not to any of the other possible interpretations of simple

blanu zdani. Furthermore,
blanu zdani refers to something which is blue in the way that houses are blue;
blanu je zdani has no such implication – the blueness of a
blanu je zdani is independent of its houseness.

With the addition of je, many more versions of “pretty little girls' school” are made possible: see Section 6.15 for a complete list.

A subtle point in the semantics of tanru like Example needs special elucidation. There are at least two possible interpretations of:

ta melbi je nixli ckule
That is-a-(beautiful and girl) type-of school.

It can be understood as:

That is a girls' school and a beautiful school.

or as:

That is a school for things which are both girls and beautiful.

The interpretation specified by Example treats the tanru as a sort of abbreviation for:

ta ke melbi ckule ke'e je ke nixli ckule [ke'e]
That is-a-( beautiful type-of school ) and ( girl type-of school )

whereas the interpretation specified by Example does not. This is a kind of semantic ambiguity for which Lojban does not compel a firm resolution. The way in which the school is said to be of type “beautiful and girl” may entail that it is separately a beautiful school and a girls' school; but the alternative interpretation, that the members of the school are beautiful and girls, is also possible. Still another interpretation is:

That is a school for beautiful things and also for girls.

so while the logical connectives help to resolve the meaning of tanru, they by no means compel a single meaning in and of themselves.

In general, logical connectives within tanru cannot undergo the formal manipulations that are possible with the related logical connectives that exist outside tanru; See Section 16.24 for further details.

The logical connective je is only one of the fourteen logical connectives that Lojban provides. Here are a few examples of some of the others:

le bajra cu jinga ja te jinga
the runner(s) is/are winner(s) or loser(s).
blanu naja lenku skapi
(blue only-if cold) skin
skin which is blue only if it is cold
xamgu jo tordu nuntavla
(good if-and-only-if short) speech
speech which is good if (and only if) it is short
vajni ju pluka nuntavla
(important whether-or-not pleasing) event-of-talking
speech which is important, whether or not it is pleasing

In Example , ja is grammatically equivalent to je but means “or” (more precisely, “and/or”). Likewise, naja means “only if” in Example , jo means “if and only if” in Example , and ju means “whether or not” in Example .

Now consider the following example:

ricfu je blanu jabo crino
rich and (blue or green)

which illustrates a new grammatical feature: the use of both ja' and bo between tanru components. The two cmavo combine to form a compound whose meaning is that of ja but which groups more closely; ja'bo is to 'ja as plain bo is to no cmavo at all. However, both ja and ja'bo group less closely than bo does:

ricfu je blanu jabo crino bo blanu
rich and (blue or green - blue)
rich and (blue or greenish-blue)

An alternative form of Example is:

ricfu je ke blanu ja crino [ke'e]
rich and (blue or green)

In addition to the logical connectives, there are also a variety of non-logical connectives, grammatically equivalent to the logical ones. The only one with a well-understood meaning in tanru contexts is joi, which is the kind of “and” that denotes a mixture:

ti blanu joi xunre bolci
This is-a-(blue and red) ball.

The ball described is neither solely red nor solely blue, but probably striped or in some other way exhibiting a combination of the two colors. Example is distinct from:

ti blanu xunre bolci
This is a bluish-red ball

which would be a ball whose color is some sort of purple tending toward red, since xunre is the more important of the two components. On the other hand,

ti blanu je xunre bolci
This is a (blue and red) ball

is probably self-contradictory, seeming to claim that the ball is independently both blue and red at the same time, although some sensible interpretation may exist.

Finally, just as English “and” has the variant form “both ... and”, so je between tanru components has the variant form gu'egi, where gu'e is placed before the components and gi between them:

gu'e barda gi xunre gerku
(both big and red) type-of dog

is equivalent in meaning to Example . For each logical connective related to je, there is a corresponding connective related to gu'egi in a systematic way.

The portion of a gu'egi construction before the gi is a full selbri, and may use any of the selbri resources including je logical connections. After the gi, logical connections are taken to be wider in scope than the gu'egi, which has in effect the same scope as bo:

gu'e barda je xunre gi gerku ja mlatu
(both (big and red) and dog) or cat
something which is either big, red, and a dog, or else a cat

leaves mlatu outside the gu'egi construction. The scope of the gi arm extends only to a single brivla or to two or more brivla connected with bo or keke'e.

Linked sumti: be-bei-be'o

The following cmavo are discussed in this section:


The question of the place structures of selbri has been glossed over so far. This chapter does not attempt to treat place structure issues in detail; they are discussed in Chapter 13. One grammatical structure related to places belongs here, however. In simple sentences such as Example , the place structure of the selbri is simply the defined place structure of the gismumamta. What about more complex selbri?

For tanru, the place structure rule is simple: the place structure of a tanru is always the place structure of its tertau. Thus, the place structure of

blanu zdani is that of zdani: the x1 place is a house or nest, and the x2 place is its occupants.

What about the places of blanu? Is there any way to get them into the act? In fact, blanu has only one place, and this is merged, as it were, with the x1 place of zdani. It is whatever is in the x1 place that is being characterized as blue-for-a-house. But if we replace blanu with xamgu, we get:

ti xamgu zdani
This is-a-good house.
This is a good (for someone, by some standard) house.

Since xamgu has three places (x1, the good thing; x2, the person for whom it is good; and x3, the standard of goodness), Example necessarily omits information about the last two: there is no room for them. Room can be made, however!

ti xamgu be do bei mi [be'o] zdani
This is-a-good (for you by-standard me) house.
This is a house that is good for you by my standards.

Here, the gismu xamgu has been followed by the cmavo be (of selma'o BE), which signals that one or more sumti follows. These sumti are not part of the overall bridi place structure, but fill the places of the brivla they are attached to, starting with x2. If there is more than one sumti, they are separated by the cmavo bei (of selma'o BEI), and the list of sumti is terminated by the elidable terminator be'o (of selma'o BEhO).

Grammatically, a brivla with sumti linked to it in this fashion plays the same role in tanru as a simple brivla. To illustrate, here is a fully fleshed-out version of Example , with all places filled in:

ti cmalu be le ka canlu bei lo'e ckule be'o
This is a small (in-dimension the property-of volume by-standard the-typical school)
nixli be li mu bei lo merko be'o bo ckule
(girl (of-years the-number five by-standard some American-thing) school)
la bryklyn. loi pemci
in-Brooklyn with-subject poems
le mela nu,IORK. prenu le jecta
for-audience New-York persons with-operator the state.

This is a school, small in volume compared to the typical school, pertaining to five-year-old girls (by American standards), in Brooklyn, teaching poetry to the New York community and operated by the state.

Here the three places of cmalu, the three of nixli, and the four of ckule are fully specified. Since the places of ckule are the places of the bridi as a whole, it was not necessary to link the sumti which follow ckule. It would have been legal to do so, however:

mi klama be le zarci bei le zdani [be'o]
I go (to-the market from-the house).

means the same as

mi klama le zarci le zdani
I go to-the market from-the house.

No matter how complex a tanru gets, the last brivla always dictates the place structure: the place structure of

melbi je cmalu nixli bo ckule
a (pretty and little) (girl school)
a school for girls which is both beautiful and small

is simply that of ckule. (The sole exception to this rule is discussed in Section 6.7.)

It is possible to precede linked sumti by the place structure ordering tags fe, fi, fo, and fu (of selma'o FA, discussed further in Section 13.2), which serve to explicitly specify the x2, x3, x4, and x5 places respectively. Normally, the place following the be is the x2 place and the other places follow in order. If it seems convenient to change the order, however, it can be accomplished as follows:

ti xamgu be fi mi bei fe do [be'o] zdani
This is-a-good ( by-standard me for you ) house.

which is equivalent in meaning to Example . Note that the order of be, bei, and be'o does not change; only the inserted fi tells us that mi is the x3 place (and correspondingly, the inserted fe tells us that do is the x2 place). Changing the order of sumti is often done to match the order of another language, or for emphasis or rhythm.

Of course, using FA cmavo makes it easy to specify one place while omitting a previous place:

ti xamgu be fi mi [be'o] zdani
This is-a-good (by-standard me) house.
This is a good house by my standards.

Similarly, sumti labeled by modal or tense tags can be inserted into strings of linked sumti just as they can into bridi:

ta blanu be ga'a mi [be'o] zdani
That is-a-blue (to-observer me) house.
That is a blue, as I see it, house.

The meaning of Example is slightly different from:

ta blanu zdani ga'a mi
That is-a-blue house to-observer me.
That is a blue house, as I see it.

See discussions in Chapter 13 of modals and in Chapter 14 of tenses for more explanations.

The terminator be'o is almost always elidable: however, if the selbri belongs to a description, then a relative clause following it will attach to the last linked sumti unless be'o is used, in which case it will attach to the outer description:

le xamgu be do noi barda cu zdani
The good-thing for you (who are-large) is-a-house.
le xamgu be do be'o noi barda cu zdani
The (good-thing for you) (which is-large) is-a-house

(Relative clauses are explained in Chapter 12.)

In other cases, however, be'o cannot be elided if ku has also been elided:

le xamgu be le ctuca [ku] be'o zdani
the good (for the teacher) house

requires either ku or be'o, and since there is only one occurrence of be, the be'o must match it, whereas it may be confusing which occurrence of le the ku terminates (in fact the second one is correct).

Inversion of tanru: co

The following cmavo is discussed in this section:


The standard order of Lojban tanru, whereby the modifier precedes what it modifies, is very natural to English-speakers: we talk of “blue houses”, not of “houses blue”. In other languages, however, such matters are differently arranged, and Lojban supports this reverse order (tertau before seltau) by inserting the particle co. Example and Example mean exactly the same thing:

ta blanu zdani
That is-a-blue type-of-house.
That is a blue house.
ta zdani co blanu
That is-a-house of-type blue.
That is a blue house.

This change is called “tanru inversion”. In tanru inversion, the element before co ( zdani in Example ) is the tertau, and the element following co ( blanu) in Example ) is the seltau.

The meaning, and more specifically, the place structure, of a tanru is not affected by inversion: the place structure of

zdani co blanu is still that of zdani. However, the existence of inversion in a selbri has a very special effect on any sumti which follow that selbri. Instead of being interpreted as filling places of the selbri, they actually fill the places (starting with x2) of the seltau. In Section 6.6, we saw how to fill interior places with bebeibe'o, and in fact Example and Example have the same meaning:
mi klama be le zarci bei le zdani be'o troci
I am-a-(goer to the market from the house) type-of trier.
I try to go to the market from the house.
mi troci co klama le zarci le zdani
I am-a-trier of-type (goer to-the market from-the house).
I try to go to the market from the house.

Example is a less deeply nested construction, requiring fewer cmavo. As a result it is probably easier to understand.

Note that in Lojban “trying to go” is expressed using troci as the tertau. The reason is that “trying to go” is a “going type of trying”, not a “trying type of going”. The trying is more fundamental than the going – if the trying fails, we may not have a going at all.

Any sumti which precede a selbri with an inverted tanru fill the places of the selbri (i.e., the places of the tertau) in the ordinary way. In Example , mi fills the x1 place of

troci co klama, which is the x1 place of troci. The other places of the selbri remain unfilled. The trailing sumti
le zarci and
le zdani do not occupy selbri places, despite appearances.

As a result, the regular mechanisms (involving selma'o VOhA and GOhI, explained in Chapter 10) for referring to individual sumti of a bridi cannot refer to any of the trailing places of Example , because they are not really “sumti of the bridi” at all.

When inverting a more complex tanru, it is possible to invert it only at the most general modifier-modified pair. The only possible inversion of Example , for instance, is:

ta nixli [bo] ckule co cmalu
That (is-a-girl type-of school) of-type little.
That's a girls' school which is small.

Note that the bo of Example is optional in Example , because co groups more loosely than any other cmavo used in tanru, including none at all. Not even keke'e parentheses can encompass a co:

ta cmalu ke nixli ckule [ke'e] co melbi
That is-a-(little type-of (girl type-of school)) of-type pretty.
That's a small school for girls which is beautiful.

In Example , the ke'e is automatically inserted before the co rather than at its usual place at the end of the selbri. As a result, there is a simple and mechanical rule for removing co from any selbri: change “A co B” to “ke B ke'e A”. (At the same time, any sumti following the selbri must be transformed into bebeibe'o form and attached following B.) Therefore,

ckule co melbi nixli
school of-type pretty girl
school for beautiful girls

means the same as:

ke melbi nixli ke'e ckule
(pretty girl) school

Multiple co cmavo can appear within a selbri, indicating multiple inversions: a right-grouping rule is employed, as for bo. The above rule can be applied to interpret such selbri, but all co cmavo must be removed simultaneously:

ckule co nixli co cmalu
school of-type (girl of-type little)

becomes formally

ke ke cmalu ke'e nixli ke'e ckule
( (little) girl ) school

which by the left-grouping rule is simply

cmalu nixli ckule
little girl school
school for little girls

As stated above, the selbri places, other than the first, of

mi klama co sutra
I am-a-goer of-type quick
I go quickly

cannot be filled by placing sumti after the selbri, because any sumti in that position fill the places of sutra, the seltau. However, the tertau places (which means in effect the selbri places) can be filled with be:

mi klama be le zarci be'o co sutra
I am-a-goer (to the store) of-type quick.
I go to the store quickly.

Other kinds of simple selbri

The following cmavo are discussed in this section:


So far we have only discussed brivla and tanru built up from brivla as possible selbri. In fact, there are a few other constructions in Lojban which are grammatically equivalent to brivla: they can be used either directly as selbri, or as components in tanru. Some of these types of simple selbri are discussed at length in Chapter 10, Chapter 16, and Chapter ELG-ERROR in Template:Lch; but for completeness these types are mentioned here with a brief explanation and an example of their use in selbri.

The cmavo of selma'o GOhA (with one exception) serve as pro-bridi, providing a reference to the content of other bridi; none of them has a fixed meaning. The most commonly used member of GOhA is probably go'i, which amounts to a repetition of the previous bridi, or part of it. If I say:

la djan. klama le zarci
John goes-to the market.

you may retort:

la djan. go'i troci
John [repeat last] are-a-tryer
John tries to.

Example is short for:

la djan. klama be le zarci be'o troci
John is-a-goer (to the market) type-of trier.

because the whole bridi of Example has been packaged up into the single word go'i and inserted into Example .

The exceptional member of GOhA is du, which represents the relation of identity. Its place structure is:

x1 is identical with x2, x3, ...

for as many places as are given. More information on selma'o GOhA is available in Chapter 10.

Lojban mathematical expressions (mekso) can be incorporated into selbri in two different ways. Mathematical operators such as su'i, meaning “plus”, can be transformed into selbri by prefixing them with nu'a (of selma'o NUhA). The resulting place structure is:

x1 is the result of applying (the operator) to arguments x2, x3, etc.

for as many arguments as are required. (The result goes in the x1 place because the number of following places may be indefinite.) For example:

li vo nu'a su'i li re li re
The-number 4 is-the-sum-of the-number 2 and-the-number 2.

A possible tanru example might be:

mi jimpe tu'a loi nu'a su'i nabmi
I understand something-about the-mass-of is-the-sum-of problems.
I understand addition problems.

More usefully, it is possible to combine a mathematical expression with a cmavo of selma'o MOI to create one of various numerical selbri. Details are available in Section 18.29. Here are a few tanru:

la prim. palvr. pamoi cusku
Preem Palver is-the-1-th speaker.
Preem Palver is the first speaker.
la an,iis. joi la .asun. bruna remei
Anyi massed-with Asun are-a-brother type-of-twosome.
Anyi and Asun are two brothers.

Finally, an important type of simple selbri which is not a brivla is the abstraction. Grammatically, abstractions are simple: a cmavo of selma'o NU, followed by a bridi, followed by the elidable terminator kei of selma'o KEI. Semantically, abstractions are an extremely subtle and powerful feature of Lojban whose full ramifications are documented in Chapter 16. A few examples:

ti nu zdile kei kumfa
This is-an-event-of amusement room.
This is an amusement room.

Example is quite distinct in meaning from:

ti zdile kumfa
This is-an-amuser room.

which suggests the meaning “a room that amuses someone”.

selbri based on sumti: me

The following cmavo are discussed in this section:


A sumti can be made into a simple selbri by preceding it with me (of selma'o ME) and following it with the elidable terminator me'u (of selma'o MEhU). This makes a selbri with the place structure

x1 is one of the referents of “[the sumti]”

which is true of the thing, or things, that are the referents of the sumti, and not of anything else. For example, consider the sumti

le ci nolraitru
the three noblest-governors
the three kings

If these are understood to be the Three Kings of Christian tradition, who arrive every year on January 6, then we may say:

la BALtazar. cu me le ci nolraitru

Balthazar is one-of-the-referents-of “the three kings”.

Balthazar is one of the three kings.

and likewise

la kaspar. cu me le ci nolraitru
Caspar is one of the three kings.


la melxi,or. cu me le ci nolraitru
Melchior is one of the three kings.

If the sumti refers to a single object, then the effect of me is much like that of du:

do du la djan.
You are-identical-with the-one-called “John”.
You are John.

means the same as

do me la djan.

You are-the-referent-of “the-one-called "John”".

You are John.

It is common to use me selbri, especially those based on name sumti using la, as seltau. For example:

ta me lai kraislr. [me'u] karce

That (is-a-referent of “the-mass-called "Chrysler"”) car.

That is a Chrysler car.

The elidable terminator me'u can usually be omitted. It is absolutely required only if the me selbri is being used in an indefinite description (a type of sumti explained in Section 8.7), and if the indefinite description is followed by a relative clause (explained in Chapter 12) or a sumti logical connective (explained in Section 16.18). Without a me'u, the relative clause or logical connective would appear to belong to the sumti embedded in the me expression. Here is a contrasting pair of sentences:

re me le ci nolraitru .e la djan. [me'u] cu blabi
Two of the group “the three kings and John” are white.
re me le ci nolraitru me'u .e la djan. cu blabi
Two of the three kings, and John, are white.

In Example the me selbri covers the three kings plus John, and the indefinite description picks out two of them that are said to be white: we cannot say which two. In Example , though, the me selbri covers only the three kings: two of them are said to be white, and so is John.

Finally, here is another example requiring me'u:

ta me la'e le se cusku be do me'u cukta
That is-a-(what-you-said) type of book.
That is the kind of book you were talking about.

There are other sentences where either me'u or some other elidable terminator must be expressed:

le me le ci nolraitru [ku] me'u nunsalci
the (the three kings) type-of-event-of-celebrating
the Three Kings celebration

requires either ku or me'u to be explicit, and (as with be'o in Section 6.6) the me'u leaves no doubt which cmavo it is paired with.

Conversion of simple selbri

Conversion is the process of changing a selbri so that its places appear in a different order. This is not the same as labeling the sumti with the cmavo of FA, as mentioned in Section 6.6, and then rearranging the order in which the sumti are spoken or written. Conversion transforms the selbri into a distinct, though closely related, selbri with renumbered places.

In Lojban, conversion is accomplished by placing a cmavo of selma'o SE before the selbri:

mi prami do
I love you.

is equivalent in meaning to:

do se prami mi
You [swap x1 and x2] love me.
You are loved by me.

Conversion is fully explained in Section 13.3. For the purposes of this chapter, the important point about conversion is that it applies only to the following simple selbri. When trying to convert a tanru, therefore, it is necessary to be careful! Consider Example :

la .alis. cu cadzu klama le zarci
Alice is-a-walker type-of goer to-the market.
Alice walkingly goes to the market.
Alice walks to the market.

To convert this sentence so that

le zarci is in the x1 place, one correct way is:
le zarci cu se ke cadzu klama [ke'e] la .alis.
The market is-a-[swap x1/x2] (walker type-of goer) Alice.
The market is-walkingly gone-to by-Alice.

The keke'e brackets cause the entire tanru to be converted by the se, which would otherwise convert only cadzu, leading to:

le zarci cu se cadzu klama la .alis.
The market (is-a-[swap x1/x2] walker) type-of goer to Alice.
The market is-a-walking-surface type-of goer to Alice.

whatever that might mean. An alternative approach, since the place structure of

cadzu klama is that of klama alone, is to convert only the latter:
le zarci cu cadzu se klama la .alis.
The market walkingly is-gone-to by-Alice.

But the tanru in Example may or may not have the same meaning as that in Example ; in particular, because cadzu is not converted, there is a suggestion that although Alice is the goer, the market is the walker. With a different sumti as x1, this seemingly odd interpretation might make considerable sense:

la djan. cu cadzu se klama la .alis
John walkingly is-gone-to by Alice

suggests that Alice is going to John, who is a moving target.

There is an alternative type of conversion, using the cmavo jai of selma'o JAI optionally followed by a modal or tense construction. Grammatically, such a combination behaves exactly like conversion using SE. More details can be found in Section 13.11.

Scalar negation of selbri

Negation is too large and complex a topic to explain fully in this chapter; See Chapter ELG-ERROR in Template:Lch. In brief, there are two main types of negation in Lojban. This section is concerned with so-called “scalar negation”, which is used to state that a true relation between the sumti is something other than what the selbri specifies. Scalar negation is expressed by cmavo of selma'o NAhE:

la .alis. cu na'e ke cadzu klama [ke'e] le zarci
Alice non- (walkingly goes) to-the market.
Alice other-than (walkingly goes) to-the market.
Alice doesn't walk to the market.

meaning that Alice's relationship to the market is something other than that of walking there. But if the ke were omitted, the result would be:

la .alis. cu na'e cadzu klama le zarci
Alice non- walkingly goes to-the market.
Alice doesn't walk to the market.

meaning that Alice does go there in some way ( klama is not negated), but by a means other than that of walking. Example negates both cadzu and klama, suggesting that Alice's relation to the market is something different from walkingly-going; it might be walking without going, or going without walking, or neither.

Of course, any of the simple selbri types explained in Section 6.8 may be used in place of brivla in any of these examples:

la djonz. cu na'e pamoi cusku
Jones is non-1st speaker
Jones is not the first speaker.

Since only pamoi is negated, an appropriate inference is that he is some other kind of speaker.

Here is an assortment of more complex examples showing the interaction of scalar negation with bo grouping, ke and ke'e grouping, logical connection, and sumti linked with be and bei:

mi na'e sutra cadzu be fi le birka be'o klama le zarci
I ( (non-quickly) ( walking using the arms) ) go-to the market.
I go to the market, walking using my arms other than quickly.

In Example , na'e negates only sutra. Contrast Example :

mi na'e ke sutra cadzu be fi le birka [be'o] ke'e klama le zarci
I non- ( quickly (walking using the arms) ) go-to the market.
I go to the market, other than by walking quickly on my arms.

Now consider Example and Example , which are equivalent in meaning, but use ke grouping and bo grouping respectively:

mi sutra cadzu be fi le birka be'o je masno klama le zarci
I (quickly – (walking using the arms) and slowly) go-to the market.
I go to the market, both quickly walking using my arms and slowly.
mi ke sutra cadzu be fi le birka [be'o] ke'e je masno klama le zarci
I ( (quickly (walking using the arms) ) and slowly) go-to the market.
I go to the market, both quickly walking using my arms and slowly.

However, if we place a na'e at the beginning of the selbri in both Example and Example , we get different results:

mi na'e sutra cadzu be fi le birka be'o je masno klama le zarci
I ( (non- quickly) - (walking using the arms) and slowly) go-to the market.
I go to the market, both walking using my arms other than quickly, and also slowly.
mi na'e ke sutra cadzu be fi le birka [be'o] ke'e je masno klama le zarci
I (non-(quickly (walking using the arms) ) and slowly) go-to the market.
I go to the market, both other than quickly walking using my arms, and also slowly.

The difference arises because the na'e in Example negates the whole construction from ke to ke'e, whereas in Example it negates sutra alone.

Beware of omitting terminators in these complex examples! If the explicit ke'e is left out in Example , it is transformed into:

mi na'e ke sutra cadzu be fi le birka be'o je masno klama [ke'e] le zarci
I non-(quickly ( (walking using the arms) ) and slowly) go-to) the market.
I do something other than quickly both going to the market walking
using my arms and slowly going to the market.

And if both ke'e and be'o are omitted, the results are even sillier:

mi na'e ke sutra cadzu be fi le birka je masno klama [be'o] [ke'e] le zarci
I non-(quickly walk on my (arm-type and slow) goers) on the market.
I do something other than quickly walking using the goers, both arm-type and slow, relative-to the market.

In Example , everything after be is a linked sumti, so the place structure is that of cadzu, whose x2 place is the surface walked upon. It is less than clear what an “arm-type goer” might be. Furthermore, since the x3 place has been occupied by the linked sumti, the

le zarci following the selbri falls into the nonexistent x4 place of cadzu. As a result, the whole example, though grammatical, is complete nonsense. (The bracketed Lojban words appear where a fluent Lojbanist would understand them to be implied.)

Finally, it is also possible to place na'e before a gu'egi logically connected tanru construction. The meaning of this usage has not yet been firmly established.

Tenses and bridi negation

A bridi can have cmavo associated with it which specify the time, place, or mode of action. For example, in

mi pu klama le zarci
I [past] go to-the market.
I went to the market.

the cmavo pu specifies that the action of the speaker going to the market takes place in the past. Tenses are explained in full detail in Chapter 14. Tense is semantically a property of the entire bridi; however, the usual syntax for tenses attaches them at the front of the selbri, as in Example . There are alternative ways of expressing tense information as well. Modals, which are explained in Chapter 13, behave in the same way as tenses.

Similarly, a bridi may have the particle na (of selma'o NA) attached to the beginning of the selbri to negate the bridi. A negated bridi expresses what is false without saying anything about what is true. Do not confuse this usage with the scalar negation of Section 6.11. For example:

la djonz. na pamoi cusku
Jones (Not!) is-the-first speaker
It is not true that Jones is the first speaker.
Jones isn't the first speaker.

Jones may be the second speaker, or not a speaker at all; Example doesn't say. There are other ways of expressing bridi negation as well; the topic is explained fully in Chapter ELG-ERROR in Template:Lch.

Various combinations of tense and bridi negation cmavo are permitted. If both are expressed, either order is permissible with no change in meaning:

mi na pu klama le zarci
mi pu na klama le zarci
It is false that I went to the market.
I didn't go to the market.

It is also possible to have more than one na, in which case pairs of na cmavo cancel out:

mi na na klama le zarci
It is false that it is false that I go to the market.
I go to the market.

It is even possible, though somewhat pointless, to have multiple na cmavo and tense cmavo mixed together, subject to the limitation that two adjacent tense cmavo will be understood as a compound tense, and must fit the grammar of tenses as explained in Chapter 14.

mi na pu na ca klama le zarci
I [not] [past] [not] [present] go to-the market
It is not the case that in the past it was not the case that in the present I went to the market.
I didn't not go to the market.
I went to the market.

Tense, modal, and negation cmavo can appear only at the beginning of the selbri. They cannot be embedded within it.

Some types of asymmetrical tanru

This section and Section 6.14 contain some example tanru classified into groups based on the type of relationship between the modifying seltau and the modified tertau. All the examples are paralleled by compounds actually observed in various natural languages. In the tables which follow, each group is preceded by a brief explanation of the relationship. The tables themselves contain a tanru, a literal gloss, an indication of the languages which exhibit a compound analogous to this tanru, and (for those tanru with no English parallel) a translation.

Here are the 3-letter abbreviations used for the various languages (it is presumed to be obvious whether a compound is found in English or not, so English is not explicitly noted):

Imbabura Quechua

Any lujvo or fu'ivla used in a group are glossed at the end of that group.

The tanru discussed in this section are asymmetrical tanru; that is, ones in which the order of the terms is fundamental to the meaning of the tanru. For example,

junla dadysli, or “clock pendulum”, is the kind of pendulum used in a clock, whereas
dadysli junla, or “pendulum clock”, is the kind of clock that employs a pendulum. Most tanru are asymmetrical in this sense. Symmetrical tanru are discussed in Section 6.14.

The tertau represents an action, and the seltau then represents the object of that action: <tab class=wikitable header=true>pinsi nunkilbra pencil sharpener Hun zgike nunctu music instruction Hun mirli nunkalte deer hunting Hun finpe nunkalte fish hunting Tur,Kor,Udm,Aba fishing smacu terkavbu mousetrap Tur,Kor,Hun,Udm,Aba zdani turni house ruler Kar host zerle'a nunte'a thief fear Skt fear of thieves cevni zekri god crime Skt offense against the gods </tab>


The tertau represents a set, and the seltau the type of the elements contained in that set: <tab class=wikitable header=true> zdani lijgri house row selci lamgri cell block karda mulgri card pack Swe rokci derxi stone heap Swe tadni girzu student group Hun remna girzu human-being group Qab group of people cpumi'i lijgri tractor column Qab cevni jenmi god army Skt cevni prenu god folk Skt </tab>


Conversely: the tertau is an element, and the seltau represents a set in which that element is contained. Implicitly, the meaning of the tertau is restricted from its usual general meaning to the specific meaning appropriate for elements in the given set. Note the opposition between

zdani linji in the previous group, and
linji zdani in this one, which shows why this kind of tanru is called “asymmetrical”.

<tab class=wikitable header=true> carvi dirgo raindrop Tur,Kor,Hun,Udm,Aba linji zdani row house </tab> The seltau specifies an object and the tertau a component or detail of that object; the tanru as a whole refers to the detail, specifying that it is a detail of that whole and not some other. <tab class=wikitable header=true> junla dadysli clock pendulum Hun purdi vorme garden door Qab purdi bitmu garden wall Que moklu skapi mouth skin Imb lips nazbi kevna nose hole Imb nostril karce xislu automobile wheel Chi jipci pimlu chicken feather Chi vinji rebla airplane tail Chi </tab>


Conversely: the seltau specifies a characteristic or important detail of the object described by the tertau; objects described by the tanru as a whole are differentiated from other similar objects by this detail. <tab class=wikitable header=true> pixra cukta picture book kerfa silka hair silk Kar velvet plise tapla apple cake Tur dadysli junla pendulum clock Hun </tab>


The tertau specifies a general class of object (a genus), and the seltau specifies a sub-class of that class (a species): <tab class=wikitable header=true> ckunu tricu pine tree Hun,Tur,Hop </tab> The tertau specifies an object of possession, and the seltau may specify the possessor (the possession may be intrinsic or otherwise). In English, these compounds have an explicit possessive element in them: “lion's mane”, “child's foot”, “noble's cow”. <tab class=wikitable header=true> cinfo kerfa lion mane Kor,Tur,Hun,Udm,Qab verba jamfu child foot Swe nixli tuple girl leg Swe cinfo jamfu lion foot Que danlu skapi animal skin Ewe ralju zdani chief house Ewe jmive munje living world Skt nobli bakni noble cow Skt nolraitru ralju king chief Skt emperor </tab>


The tertau specifies a habitat, and the seltau specifies the inhabitant: <tab class=wikitable header=true> lanzu tumla family land </tab> The tertau specifies a causative agent, and the seltau specifies the effect of that cause: <tab class=wikitable header=true> kalselvi'i gapci tear gas Hun terbi'a jurme disease germ Tur fenki litki crazy liquid Hop whisky pinca litki urine liquid Hop beer </tab>


Conversely: the tertau specifies an effect, and the seltau specifies its cause. <tab class=wikitable header=true> djacu barna water mark Chi </tab> The tertau specifies an instrument, and the seltau specifies the purpose of that instrument: <tab class=wikitable header=true> taxfu dadgreku garment rack Chi tergu'i ti'otci lamp shade Chi xirma zdani horse house Chi stall nuzba tanbo news board Chi bulletin board </tab>

source of illumination

More vaguely: the tertau specifies an instrument, and the seltau specifies the object of the purpose for which that instrument is used: <tab class=wikitable header=true> cpina rokci pepper stone Que stone for grinding pepper jamfu djacu foot water Skt water for washing the feet grana mudri post wood Skt wood for making a post moklu djacu mouth water Hun water for washing the mouth lanme gerku sheep dog dog for working sheep </tab> The tertau specifies a product from some source, and the seltau specifies the source of the product: <tab class=wikitable header=true> moklu djacu mouth water Aba,Qab saliva ractu mapku rabbit hat Rus jipci sovda chicken egg Chi sikcurnu silka silkworm silk Chi mlatu kalci cat feces Chi bifce lakse bee wax Chi beeswax cribe rectu bear meat Tur,Kor,Hun,Udm,Aba solxrula grasu sunflower oil Tur,Kor,Hun,Udm,Aba bifce jisra bee juice Hop honey tatru litki breast liquid Hop milk kanla djacu eye water Kor tear </tab>


Conversely: the tertau specifies the source of a product, and the seltau specifies the product: <tab class=wikitable header=true> silna jinto salt well Chi kolme terkakpa coal mine Chi ctile jinto oil well Chi </tab>

source of digging

The tertau specifies an object, and the seltau specifies the material from which the object is made. This case is especially interesting, because the referent of the tertau may normally be made from just one kind of material, which is then overridden in the tanru. <tab class=wikitable header=true> rokci cinfo stone lion snime nanmu snow man Hun kliti cipni clay bird blaci kanla glass eye Hun blaci kanla glass eye Que spectacles solji sicni gold coin Tur solji junla gold watch Tur,Kor,Hun solji djine gold ring Udm,Aba,Que rokci zdani stone house Imb mudri zdani wood house Ewe wooden house rokci bitmu stone wall Ewe solji carce gold chariot Skt mudri xarci wood weapon Skt wooden weapon cmaro'i dargu pebble road Chi sudysrasu cutci straw shoe Chi </tab>


Note: the two senses of

blaci kanla can be discriminated as:

<tab class=wikitable header=true> blaci kanla bo tarmi glass (eye shape) glass eye blaci kanla bo sidju glass (eye helper) spectacles </tab> The tertau specifies a typical object used to measure a quantity and the seltau specifies something measured. The tanru as a whole refers to a given quantity of the thing being measured. English does not have compounds of this form, as a rule. <tab class=wikitable header=true> tumla spisa land piece Tur piece of land tcati kabri tea cup Kor,Aba cup of tea nanba spisa bread piece Kor piece of bread bukpu spisa cloth piece Udm,Aba piece of cloth djacu calkyguzme water calabash Ewe calabash of water </tab>

shell-fruit, calabash

The tertau specifies an object with certain implicit properties, and the seltau overrides one of those implicit properties: <tab class=wikitable header=true> kensa bloti spaceship bakni verba cattle child Ewe calf </tab> The seltau specifies a whole, and the tertau specifies a part which normally is associated with a different whole. The tanru then refers to a part of the seltau which stands in the same relationship to the whole seltau as the tertau stands to its typical whole. <tab class=wikitable header=true> kosta degji coat finger Hun coat sleeve denci genja tooth root Imb tricu stedu tree head Imb treetop </tab> The tertau specifies the producer of a certain product, and the seltau specifies the product. In this way, the tanru as a whole distinguishes its referents from other referents of the tertau which do not produce the product. <tab class=wikitable header=true> silka curnu silkworm Tur,Hun,Aba </tab> The tertau specifies an object, and the seltau specifies another object which has a characteristic property. The tanru as a whole refers to those referents of the tertau which possess the property. <tab class=wikitable header=true> sonci manti soldier ant ninmu bakni woman cattle Imb cow mamta degji mother finger Imb thumb cifnu degji baby finger Imb pinky pacraistu zdani hell house Skt fagri dapma fire curse Skt curse destructive as fire </tab>


As a particular case (when the property is that of resemblance): the seltau specifies an object which the referent of the tanru resembles. <tab class=wikitable header=true> grutrceraso jbama cherry bomb solji kerfa gold hair Hun golden hair kanla djacu eye water Kar spring bakni rokci bull stone Mon boulder </tab>

fu'ivla for “cherry” based on Linnean name

The seltau specifies a place, and the tertau an object characteristically located in or at that place. <tab class=wikitable header=true> ckana boxfo bed sheet Chi mrostu mojysu'a tomb monument Chi tombstone jubme tergusni table lamp Chi foldi smacu field mouse Chi briju ci'ajbu office desk Chi rirxe xirma river horse Chi hippopotamus xamsi gerku sea dog Chi seal cagyce'u zdani village house Skt </tab>


Specifically: the tertau is a place where the seltau is sold or made available to the public. <tab class=wikitable header=true> cidja barja food bar Chi restaurant cukta barja book bar Chi library </tab> The seltau specifies the locus of application of the tertau. <tab class=wikitable header=true> kanla velmikce eye medicine Chi jgalu grasu nail oil Chi nail polish denci pesxu tooth paste Chi </tab>

treatment used by doctor

The tertau specifies an implement used in the activity denoted by the seltau. <tab class=wikitable header=true> me la pinpan. bolci Ping-Pong ball Chi </tab> The tertau specifies a protective device against the undesirable features of the referent of the seltau. <tab class=wikitable header=true> carvi mapku rain cap Chi carvi taxfu rain garment Chi raincoat vindu firgai poison mask Chi gas mask </tab>


The tertau specifies a container characteristically used to hold the referent of the seltau. <tab class=wikitable header=true> cukta vasru book vessel Chi satchel vanju kabri wine cup Chi spatrkoka lanka coca basket Que rismi dakli rice bag Ewe,Chi tcati kabri tea cup Chi ladru botpi milk bottle Chi rismi patxu rice pot Chi festi lante trash can Chi bifce zdani bee house Kor beehive cladakyxa'i zdani sword house Kor sheath manti zdani ant nest Gua anthill </tab>

fu'ivla for “coca”

The seltau specifies the characteristic time of the event specified by the tertau. <tab class=wikitable header=true> vensa djedi spring day Chi crisa citsi summer season Chi cerni bumru morning fog Chi critu lunra autumn moon Chi dunra nicte winter night Chi nicte ckule night school Chi </tab> The seltau specifies a source of energy for the referent of the tertau. <tab class=wikitable header=true> dikca tergusni electric lamp Chi ratni nejni atom energy Chi brife molki windmill Tur,Kor,Hun,Udm,Aba </tab>


Finally, some tanru which don't fall into any of the above categories. <tab class=wikitable header=true> ladru denci milk tooth Tur,Hun,Udm,Qab kanla denci eye tooth </tab> It is clear that “tooth” is being specified, and that “milk” and “eye” act as modifiers. However, the relationship between ladru and denci is something like “tooth which one has when one is drinking milk from one's mother”, a relationship certainly present nowhere except in this particular concept. As for

kanla denci, the relationship is not only not present on the surface, it is hardly possible to formulate it at all.

Some types of symmetrical tanru

This section deals with symmetrical tanru, where order is not important. Many of these tanru can be expressed with a logical or non-logical connective between the components.

The tanru may refer to things which are correctly specified by both tanru components. Some of these instances may also be seen as asymmetrical tanru where the seltau specifies a material. The connective je is appropriate: <tab class=wikitable header=true> cipnrstrigi pacru'i owl demon Skt nolraitru prije royal sage Skt remna nakni human-being male Qab man remna fetsi human-being female Qab woman sonci tolvri soldier coward Que panzi nanmu offspring man Ewe son panzi ninmu offspring woman Ewe daughter solji sicni gold coin Tur solji junla gold watch Tur,Kor,Hun solji djine gold ring Udm,Aba,Que rokci zdani stone house Imb mudri zdani wooden house Ewe rokci bitmu stone wall Ewe solji carce gold chariot Skt mudri xarci wooden weapon Skt zdani tcadu home town Chi </tab>

fu'ivla for “owl” based on Linnean name

The tanru may refer to all things which are specified by either of the tanru components. The connective ja is appropriate: <tab class=wikitable header=true> nunji'a nunterji'a victory defeat Skt victory or defeat donri nicte day night Skt day and night lunra tarci moon stars Skt moon and stars patfu mamta father mother Imb,Kaz,Chi parents tuple birka leg arm Kaz extremity nuncti nunpinxe eating drinking Udm cuisine bersa tixnu son daughter Chi children </tab>


Alternatively, the tanru may refer to things which are specified by either of the tanru components or by some more inclusive class of things which the components typify: <tab class=wikitable header=true> curnu jalra worm beetle Mon insect jalra curnu beetle worm Mon insect kabri palta cup plate Kaz crockery jipci gunse hen goose Qab housefowl xrula tricu flower tree Chi vegetation </tab> The tanru components specify crucial or typical parts of the referent of the tanru as a whole: <tab class=wikitable header=true> tumla vacri land air Fin world moklu stedu mouth head Aba face sudysrasu cunmi hay millet Qab agriculture gugde ciste state system Mon politics prenu so'imei people multitude Mon masses djacu dertu water earth Chi climate </tab>


“Pretty little girls' school”: forty ways to say it

The following examples show every possible grouping arrangement of

'melbi cmalu nixli ckule using bo or keke'e for grouping and je or je'bo for logical connection. Most of these are definitely not plausible interpretations of the English phrase “pretty little girls' school”, especially those which describe something which is both a girl and a school.

Examples Example , Example , Example , Example , and Example are repeated here as Examples Example , Example , Example , Example , and Example respectively. The seven examples following each of these share the same grouping pattern, but differ in the presence or absence of je at each possible site. Some of the examples have more than one Lojban version. In that case, they differ only in grouping mechanism, and are always equivalent in meaning.

The logical connective je is associative: that is, “A and (B and C)” is the same as “(A and B) and C”. Therefore, some of the examples have the same meaning as others. In particular, Example , Example , Example , Example , and Example all have the same meaning because all four brivla are logically connected and the grouping is simply irrelevant. Other equivalent forms are noted in the examples themselves. However, if je were replaced by naja or jo or most of the other logical connectives, the meanings would become distinct.

It must be emphasized that, because of the ambiguity of all tanru, the English translations are by no means definitive – they represent only one possible interpretation of the corresponding Lojban sentence.

melbi cmalu nixli ckule
((pretty type-of little) type-of girl) type-of school
school for girls who are beautifully small
melbi je cmalu nixli ckule
((pretty and little) type-of girl) type-of school
school for girls who are beautiful and small
melbi bo cmalu je nixli ckule
((pretty type-of little) and girl) type-of school
school for girls and for beautifully small things
ke melbi cmalu nixli ke'e je ckule
((pretty type-of little) type-of girl) and school
thing which is a school and a beautifully small girl
melbi je cmalu je nixli ckule
((pretty and little) and girl) type-of school
school for things which are beautiful, small, and girls

Note: same as Example

melbi bo cmalu je nixli je ckule
((pretty type-of little) and girl) and school
thing which is beautifully small, a school, and a girl

Note: same as Example

ke melbi je cmalu nixli ke'e je ckule
((pretty and little) type-of girl) and school
thing which is a school and a girl who is both beautiful and small
melbi je cmalu je nixli je ckule
((pretty and little) and girl) and school
thing which is beautiful, small, a girl, and a school
melbi cmalu nixli bo ckule
(pretty type-of little) type-of (girl type-of school)
girls' school which is beautifully small
melbi je cmalu nixli bo ckule
(pretty and little) type-of (girl type-of school)
girls' school which is beautiful and small
melbi cmalu nixli je ckule
(pretty type-of little) type-of (girl and school)
something which is a girl and a school which is beautifully small
melbi bo cmalu je nixli bo ckule
(pretty type-of little) and (girl type-of school)
something which is beautifully small and a girls' school
melbi je cmalu nixli je ckule
(pretty and little) type-of (girl and school)
a pretty and little type of thing which is both a girl and a school
melbi bo cmalu je nixli jebo ckule
(pretty type-of little) and (girl and school)
thing which is beautifully small, a school, and a girl

Note: same as Example

melbi jebo cmalu je nixli bo ckule
(pretty and little) and (girl type-of school)
thing which is beautiful and small and a girl's school

Note: same as Example

melbi jebo cmalu je nixli jebo ckule
(pretty and little) and (girl and school)
thing which is beautiful, small, a girl, and a school
melbi cmalu bo nixli ckule
(pretty type-of (little type-of girl)) type-of school
school for beautiful girls who are small
melbi cmalu je nixli ckule
(pretty type-of (little and girl)) type-of school
school for beautiful things which are small and are girls
melbi je cmalu bo nixli ckule
(pretty and (little type-of girl)) type-of school
school for things which are beautiful and are small girls
ke melbi cmalu bo nixli ke'e je ckule
melbi bo cmalu bo nixli je ckule
(pretty type-of (little type-of girl)) and school
thing which is a school and a small girl who is beautiful
melbi je cmalu jebo nixli ckule
(pretty and (little and girl)) type-of school
school for things which are beautiful, small, and girls

Note: same as Example

melbi je cmalu bo nixli je ckule
(pretty and (little type-of girl)) and school
thing which is beautiful, a small girl, and a school

Note: same as Example

ke melbi cmalu je nixli ke'e je ckule
(pretty type-of (little and girl)) and school
thing which is beautifully small, a beautiful girl, and a school
melbi je cmalu jebo nixli je ckule
(pretty and (little and girl)) and school
thing which is beautiful, small, a girl, and a school
melbi cmalu bo nixli bo ckule
melbi ke cmalu ke nixli ckule [ke'e] [ke'e]
pretty type-of (little type-of (girl type-of school))
small school for girls which is beautiful
melbi ke cmalu nixli je ckule [ke'e]
pretty type-of (little type-of (girl and school))
small thing, both a girl and a school, which is beautiful
melbi cmalu je nixli bo ckule
pretty type-of (little and (girl type-of school))
thing which is beautifully small and a girls' school that is beautiful
melbi je cmalu bo nixli bo ckule
melbi je ke cmalu nixli bo ckule [ke'e]
melbi je ke cmalu ke nixli ckule [ke'e] [ke'e]
pretty and (little type-of (girl type-of school))
thing which is beautiful and a small type of girls' school
melbi cmalu je nixli jebo ckule
melbi cmalu je ke nixli je ckule [ke'e]
pretty type-of (little and (girl and school))
thing which is beautifully small, a beautiful girl, and a beautiful school

Note: same as Example

melbi je cmalu jebo nixli bo ckule
melbi je ke cmalu je nixli bo ckule [ke'e]
pretty and (little and (girl type-of school))
thing which is beautiful, small and a girls' school

Note: same as Example

melbi je ke cmalu nixli je ckule [ke'e]
pretty and (little type-of (girl and school))
beautiful thing which is a small girl and a small school
melbi jebo cmalu jebo nixli jebo ckule
pretty and (little and (girl and school))
thing which is beautiful, small, a girl, and a school
melbi ke cmalu nixli ckule [ke'e]
pretty type-of ((little type-of girl) type-of school)
beautiful school for small girls
melbi ke cmalu je nixli ckule [ke'e]
pretty type-of ((little and girl) type-of school
beautiful school for things which are small and are girls
melbi ke cmalu bo nixli je ckule [ke'e]
pretty type-of ((little type-of girl) and school)
beautiful thing which is a small girl and a school
melbi je ke cmalu nixli ckule [ke'e]
pretty and ((little type-of girl) type-of school)
thing which is beautiful and a school for small girls
melbi cmalu je nixli je ckule
pretty type-of ((little and girl) and school)
thing which is beautifully small, a beautiful girl, and a beautiful school

Note: same as Example

melbi je ke cmalu bo nixli je ckule [ke'e]
pretty and ((little type-of girl) and school)
thing which is beautiful, a small girl and a school

Note: same as Example

melbi je ke cmalu je nixli ckule [ke'e]
pretty and ((little and girl) type-of school)
thing which is beautiful and is a small school and a girls' school
melbi je ke cmalu je nixli je ckule [ke'e]
pretty and ((little and girl) and school)
thing which is beautiful, small, a girl, and a school

Sumti (nouns)

The five kinds of simple sumti

If you understand anything about Lojban, you know what a sumti is by now, right? An argument, one of those things that fills the places of simple Lojban sentences like:

mi klama le zarci
I go-to the market

In Example , mi and

le zarci are the sumti. It is easy to see that these two sumti are not of the same kind: mi is a pro-sumti (the Lojban analogue of a pronoun) referring to the speaker, whereas
le zarci is a description which refers to something described as being a market.

There are five kinds of simple sumti provided by Lojban:

  • descriptions like
le zarci, which usually begin with a descriptor (called a gadri in Lojban) such as


  • pro-sumti, such as mi;
  • names, such as
la lojban., which usually begin with la;
  • quotations, which begin with lu, le'u, zo, or zoi;
  • pure numbers, which usually begin with li.

Here are a few examples of each kind of sumti:

e'osai ko sarji la lojban.
Please support Lojban!

Example exhibits ko, a pro-sumti; and

la lojban., a name.
mi cusku lu e'osai li'u le tcidu
I express “Please!” to-the reader.
     Example  exhibits mi, a pro-sumti; 
lu e'osai li'u, a quotation; and
le tcidu, a description.
ti mitre li ci
This measures-in-meters the-number three.
This is three meters long.
 Example  exhibits ti, a pro-sumti; and 
li ci, a number.

Most of this chapter is about descriptions, as they have the most complicated syntax and usage. Some attention is also given to names, which are closely interwoven with descriptions. Pro-sumti, numbers, and quotations are described in more detail in Chapter 10, Chapter ELG-ERROR in Template:Lch, and Chapter ELG-ERROR in Template:Lch respectively, so this chapter only gives summaries of their forms and uses. See Section 8.12 through Section 8.14 for these summaries.

The three basic description types

The following cmavo are discussed in this section:


The syntax of descriptions is fairly complex, and not all of it can be explained within the confines of this chapter: relative clauses, in particular, are discussed in Chapter 12. However, most descriptions have just two components: a descriptor belonging to selma'o LE or LA, and a selbri. (The difference between selma'o LE and selma'o LA is not important until Section 8.11.) Furthermore, the selbri is often just a single brivla. Here is an elementary example:

le zarci
one-or-more-specific-things-each-of-which-I-describe-as being-a-market
the market

The long gloss for le is of course far too long to use most of the time, and in fact le is quite close in meaning to English “the”. It has particular implications, however, which “the” does not have.

The general purpose of all descriptors is to create a sumti which might occur in the x1 place of the selbri belonging to the description. Thus

le zarci conveys something which might be found in the x1 place of zarci, namely a market.

The specific purpose of le is twofold. First, it indicates that the speaker has one or more specific markets in mind (whether or not the listener knows which ones they are). Second, it also indicates that the speaker is merely describing the things he or she has in mind as markets, without being committed to the truth of that description.

le zarci cu barda
One-or-more-specific-things-which-I-describe as “markets” is/are-big.
The market is big.
The markets are big.

Note that English-speakers must state whether a reference to markets is to just one ( “the market”) or to more than one ( “the markets”). Lojban requires no such forced choice, so both colloquial translations of Example are valid. Only the context can specify which is meant. (This rule does not mean that Lojban has no way of specifying the number of markets in such a case: that mechanism is explained in Section 8.6.)

Now consider the following strange-looking example:

le nanmu cu ninmu
One-or-more-specific-things-which-I-describe as “men” are women.
The man is a woman.
The men are women.

Example is not self-contradictory in Lojban, because

le nanmu merely means something or other which, for my present purposes, I choose to describe as a man, whether or not it really is a man. A plausible instance would be: someone we had assumed to be a man at a distance turned out to be actually a woman on closer observation. Example is what I would say to point out my observation to you.

In all descriptions with le, the listener is presumed to either know what I have in mind or else not to be concerned at present (perhaps I will give more identifying details later). In particular, I might be pointing at the supposed man or men: Example would then be perfectly intelligible, since

le nanmu merely clarifies that I am pointing at the supposed man, not at a landscape, or a nose, which happens to lie in the same direction.

The second descriptor dealt with in this section is lo. Unlike le, lo is nonspecific:

lo zarci
one-or-more-of-all-the-things-which-really are-markets
a market
some markets

Again, there are two colloquial English translations. The effect of using lo in Example is to refer generally to one or more markets, without being specific about which. Unlike

le zarci,
lo zarci must refer to something which actually is a market (that is, which can appear in the x1 place of a truthful bridi whose selbri is zarci). Thus
lo nanmu cu ninmu
Some man is a woman.
Some men are women.

must be false in Lojban, given that there are no objects in the real world which are both men and women. Pointing at some specific men or women would not make Example true, because those specific individuals are no more both-men-and-women than any others. In general, lo refers to whatever individuals meet its description.

The last descriptor of this section is la, which indicates that the selbri which follows it has been dissociated from its normal meaning and is being used as a name. Like le descriptions, la descriptions are implicitly restricted to those I have in mind. (Do not confuse this use of la with its use before regular Lojbanized names, which is discussed in Section 8.11.) For example:

la cribe pu finti le lisri

The-one-named “bear” [past] creates the story.

Bear wrote the story.

In Example ,

la cribe refers to someone whose naming predicate is

cribe, i.e. “Bear”. In English, most names don't mean anything, or at least not anything obvious. The name “Frank” coincides with the English word “frank”, meaning “honest”, and so one way of translating “Frank ate some cheese” into Lojban would be:

la stace pu citka lo cirla
The-one-called “Honest/Frank” [past] eats some cheese.

English-speakers typically would not do this, as we tend to be more attached to the sound of our names than their meaning, even if the meaning (etymological or current) is known. Speakers of other languages may feel differently. (In point of fact, “Frank” originally meant “the free one” rather than “the honest one”.)

It is important to note the differences between Example and the following:

le cribe pu finti le lisri
One-or-more-specific-things-which-I-describe-as a-bear [past] creates the story.
The bear(s) wrote the story.
lo cribe pu finti le lisri
One-or-more-of-the-things-which-really are-bears [past] creates the story.
A bear wrote the story.
Some bears wrote the story.

Example is about a specific bear or bearlike thing(s), or thing(s) which the speaker (perhaps whimsically or metaphorically) describes as a bear (or more than one); Example is about one or more of the really existing, objectively defined bears. In either case, though, each of them must have contributed to the writing of the story, if more than one bear (or “bear”) is meant.

(The notion of a “really existing, objectively defined bear” raises certain difficulties. Is a panda bear a “real bear”? How about a teddy bear? In general, the answer is “yes”. Lojban gismu are defined as broadly as possible, allowing tanru and lujvo to narrow down the definition. There probably are no necessary and sufficient conditions for defining what is and what is not a bear that can be pinned down with complete precision: the real world is fuzzy. In borderline cases, le may communicate better than lo.)

So while Example could easily be true (there is a real writer named “Greg Bear”), and Example could be true if the speaker is sufficiently peculiar in what he or she describes as a bear, Example is certainly false.

Similarly, compare the following two examples, which are analogous to Example and Example respectively:

le remna pu finti le lisri
The human being(s) wrote the story.
lo remna pu finti le lisri
A human being wrote the story.
Some human beings wrote the story.

Example says who the author of the story is: one or more particular human beings that the speaker has in mind. If the topic of conversation is the story, then Example identifies the author as someone who can be pointed out or who has been previously mentioned; whereas if the topic is a person, then

le remna is in effect a shorthand reference to that person. Example merely says that the author is human.

The elidable terminator for all descriptions is ku. It can almost always be omitted with no danger of ambiguity. The main exceptions are in certain uses of relative clauses, which are discussed in Section 12.5, and in the case of a description immediately preceding the selbri. In this latter case, using an explicit cu before the selbri makes the ku unnecessary. There are also a few other uses of ku: in the compound negator

naku (discussed in Chapter 17) and to terminate place-structure, tense, and modal tags that do not have associated sumti (discussed in Chapter 13 and Chapter 14).

Individuals and masses

The following cmavo are discussed in this section:


All Lojban sumti are classified by whether they refer to one of three types of objects, known as “individuals”, “masses”, and “sets”. The term “individual” is misleading when used to refer to more than one object, but no less-confusing term has as yet been found. All the descriptions in Section and Section 8.1 refer to individuals, whether one or more than one. Consider the following example:

le prenu cu bevri le pipno
One-or-more-of-those-I-describe-as persons carry the piano.
The person(s) carry the piano.

(Of course the second le should really get the same translation as the first, but I am putting the focus of this discussion on the first le, the one preceding prenu. I will assume that there is only one piano under discussion.)

Suppose the context of Example is such that you can determine that I am talking about three persons. What am I claiming? I am claiming that each of the three persons carried the piano. This claim can be true if the persons carried the piano one at a time, or in turns, or in a variety of other ways. But in order for Example to be true, I must be willing to assert that person 1 carried the piano, and that person 2 carried the piano, and that person 3 carried the piano.

But suppose I am not willing to claim that. For in fact pianos are heavy, and very few persons can carry a piano all by themselves. The most likely factual situation is that person 1 carried one end of the piano, and person 2 the other end, while person 3 either held up the middle or else supervised the whole operation without actually lifting anything. The correct way of expressing such a situation in Lojban is:

lei prenu cu bevri le pipno
The-mass-of-one-or-more-of-those-I-describe-as persons carry the piano.

Here the same three persons are treated not as individuals, but as a so-called “mass entity”, or just “mass”. A mass has the properties of each individual which composes it, and may have other properties of its own as well. This can lead to apparent contradictions. Thus suppose in the piano-moving example above that person 1 has fair skin, whereas person 2 has dark skin. Then it is correct to say that the person-mass has both fair skin and dark skin. Using the mass descriptor lei signals that ordinary logical reasoning is not applicable: contradictions can be maintained, and all sorts of other peculiarities may exist. However, we can safely say that a mass inherits only the component properties that are relevant to it; it would be ludicrous to say that a mass of two persons is of molecular dimensions, simply because some of the parts (namely, the molecules) of the persons are that small.

The descriptors loi and lai are analogous to lo and la respectively, but refer to masses either by property ( loi) or by name ( lai). A classic example of loi use is:

loi cinfo cu xabju le fi'ortu'a
Part-of-the-mass-of-those-which-really are-lions dwell in-the African-land.
The lion dwells in Africa.
Lions dwell in Africa.

The difference between lei and loi is that

lei cinfo refers to a mass of specific individuals which the speaker calls lions, whereas
loi cinfo refers to some part of the mass of all those individuals which actually are lions. The restriction to “some part of the mass” allows statements like Example to be true even though some lions do not dwell in Africa – they live in various zoos around the world. On the other hand, Example doesn't actually say that most lions live in Africa: equally true is
loi glipre cu xabju le fi'ortu'a
Part-of-the-mass-of-those-which-really are-English-persons dwell in-the African-land.
The English dwell in Africa.

since there is at least one English person living there. Section 8.3 explains another method of saying what is usually meant by “The lion lives in Africa” which does imply that living in Africa is normal, not exceptional, for lions.

Note that the Lojban mass articles are sometimes translated by English plurals (the most usual case), sometimes by English singulars (when the singular is used to express typicalness or abstraction), and sometimes by singulars with no article:

loi matne cu ranti
Part-of-the-mass-of-that-which-really is-a-quantity-of-butter is-soft.
Butter is soft.

Of course, some butter is hard (for example, if it is frozen butter), so the “part-of” implication of loi becomes once again useful. The reason this mechanism works is that the English words like “butter”, which are seen as already describing masses, are translated in Lojban by non-mass forms. The place structure of matne is “x1 is a quantity of butter from source x2”, so the single English word “butter” is translated as something like “a part of the mass formed from all the quantities of butter that exist”. (Note that the operation of forming a mass entity does not imply, in Lojban, that the components of the mass are necessarily close to one another or even related in any way other than conceptually. Masses are formed by the speaker's intention to form a mass, and can in principle contain anything.)

The mass name descriptor lai is used in circumstances where we wish to talk about a mass of things identified by a name which is common to all of them. It is not used to identify a mass by a single name peculiar to it. Thus the mass version of Example ,

lai cribe pu finti le vi cukta

The-mass-of-those-named “bear” [past] creates the nearby book.

The Bears wrote this book.

in a context where

la cribe would be understood as plural, would mean that either Tom Bear or Fred Bear (to make up some names) might have written the book, or that Tom and Fred might have written it as collaborators. Using

la instead of lai in Example would give the implication that each of Tom and Fred, considered individually, had written it.

Masses and sets

The following cmavo are discussed in this section:


Having said so much about masses, let us turn to sets. Sets are easier to understand than masses, but are more rarely used. Like a mass, a set is an abstract object formed from a number of individuals; however, the properties of a set are not derived from any of the properties of the individuals that compose it.

Sets have properties like cardinality (how many elements in the set), membership (the relationship between a set and its elements), and set inclusion (the relationship between two sets, one of which – the superset – contains all the elements of the other – the subset). The set descriptors le'i, lo'i and la'i correspond exactly to the mass descriptors lei, loi, and lai except that normally we talk of the whole of a set, not just part of it. Here are some examples contrasting lo, loi, and lo'i:

lo ratcu cu bunre
One-or-more-of-those-which-really-are rats are-brown.
Some rats are brown.
loi ratcu cu cmalu
Part-of-the-mass-of-those-which-really-are rats are-small.
Rats are small.
lo'i ratcu cu barda
The-set-of rats is-large.
There are a lot of rats.

The mass of rats is small because at least one rat is small; the mass of rats is also large; the set of rats, though, is unquestionably large – it has billions of members. The mass of rats is also brown, since some of its components are; but it would be incorrect to call the set of rats brown – brown-ness is not the sort of property that sets possess.

Lojban speakers should generally think twice before employing the set descriptors. However, certain predicates have places that require set sumti to fill them. For example, the place structure of fadni is:

x1 is ordinary/common/typical/usual in property x2 among the members of set x3

Why is it necessary for the x3 place of fadni to be a set? Because it makes no sense for an individual to be typical of another individual: an individual is typical of a group. In order to make sure that the bridi containing fadni is about an entire group, its x3 place must be filled with a set:

mi fadni zo'e lo'i lobypli
I am-ordinary among the-set-of Lojban-users.
I am a typical Lojban user.

Note that the x2 place has been omitted; I am not specifying in exactly which way I am typical – whether in language knowledge, or age, or interests, or something else. If lo'i were changed to lo in Example , the meaning would be something like “I am typical of some Lojban user”, which is nonsense.

Descriptors for typical objects

The following cmavo are discussed in this section:


As promised in Section 8.2, Lojban has a method for discriminating between “the lion” who lives in Africa and “the Englishman” who, generally speaking, doesn't live in Africa even though some Englishmen do. The descriptor lo'e means “the typical”, as in

lo'e cinfo cu xabju le fi'ortu'a
The-typical lion dwells-in the African-land.
The lion dwells in Africa.

What is this “typical lion”? Surely it is not any particular lion, because no lion has all of the “typical” characteristics, and (worse yet) some characteristics that all real lions have can't be viewed as typical. For example, all real lions are either male or female, but it would be bizarre to suppose that the typical lion is either one. So the typical lion has no particular sex, but does have a color (golden brown), a residence (Africa), a diet (game), and so on. Likewise we can say that

lo'e glipre cu xabju le fi'ortu'a na.e le gligugde
The-typical English-person dwells-in the African-land (Not!) and the English-country.
The typical English person dwells not in Africa but in England.

The relationship between

lo'e cinfo and
lo'i cinfo may be explained thus: the typical lion is an imaginary lion-abstraction which best exemplifies the set of lions. There is a similar relationship between le'e and le'i:
le'e xelso merko cu gusta ponse
The-stereotypical Greek-type-of American is-a-restaurant-type-of owner.
Lots of Greek-Americans own restaurants.

Here we are concerned not with the actual set of Greek-Americans, but with the set of those the speaker has in mind, which is typified by one (real or imaginary) who owns a restaurant. The word “stereotypical” is often derogatory in English, but le'e need not be derogatory in Lojban: it simply suggests that the example is typical in the speaker's imagination rather than in some objectively agreed-upon way. Of course, different speakers may disagree about what the features of “the typical lion” are (some would include having a short intestine, whereas others would know nothing of lions' intestines), so the distinction between

lo'e cinfo and
le'e cinfo may be very fine.


le'e skina cu se finti ne'i la xali,uyd.
The-stereotypical movie is-invented in Hollywood.

is probably true to an American, but might be false (not the stereotype) to someone living in India or Russia.

Note that there is no naming equivalent of lo'e and le'e, because there is no need, as a rule, for a “typical George” or a “typical Smith”. People or things who share a common name do not, in general, have any other common attributes worth mentioning.

Quantified sumti

The following cmavo are discussed in this section:


Quantifiers tell us how many: in the case of quantifiers with sumti, how many things we are talking about. In Lojban, quantifiers are expressed by numbers and mathematical expressions: a large topic discussed in some detail in Chapter ELG-ERROR in Template:Lch. For the purposes of this chapter, a simplified treatment will suffice. Our examples will employ either the simple Lojban numbers pa, re, ci, vo, and mu, meaning “one”, “two”, “three”, “four”, “five” respectively, or else one of four special quantifiers, two of which are discussed in this section and listed above. These four quantifiers are important because every Lojban sumti has either one or two of them implicitly present in it – which one or two depends on the particular kind of sumti. There is more explanation of implicit quantifiers later in this section. (The other two quantifiers, piro and pisu'o, are explained in Section 8.6.)

Every Lojban sumti may optionally be preceded by an explicit quantifier. The purpose of this quantifier is to specify how many of the things referred to by the sumti are being talked about. Here are some simple examples contrasting sumti with and without explicit quantifiers:

do cadzu le bisli
You walk-on the ice.
re do cadzu le bisli
Two-of you walk-on the ice.

The difference between Example and Example is the presence of the explicit quantifier re in the latter example. Although re by itself means “two”, when used as a quantifier it means “two-of”. Out of the group of listeners (the number of which isn't stated), two (we are not told which ones) are asserted to be “walkers on the ice”. Implicitly, the others (if any) are not walkers on the ice. In Lojban, you cannot say “I own three shoes” if in fact you own four shoes. Numbers need never be specified, but if they are specified they must be correct.

(This rule does not mean that there is no way to specify a number which is vague. The sentence

mi ponse su'o ci cutci
I possess at-least three shoes.

is true if you own three shoes, or four, or indeed any larger number. More details on vague numbers appear in the discussion of mathematical expressions in Chapter ELG-ERROR in Template:Lch.)

Now consider Example again. How many of the listeners are claimed to walk on the ice? The answer turns out to be: all of them, however many that is. So Example and Example :

ro do cadzu le bisli
All-of you walk-on the ice.

turn out to mean exactly the same thing. This is a safe strategy, because if one of my listeners doesn't turn out to be walking on the ice, I can safely claim that I didn't intend that person to be a listener! And in fact, all of the personal pro-sumti such as mi and mi'o and ko obey the same rule. We say that personal pro-sumti have a so-called “implicit quantifier” of ro (all). This just means that if no quantifier is given explicitly, the meaning is the same as if the implicit quantifier had been used.

Not all sumti have ro as the implicit quantifier, however. Consider the quotation in:

mi cusku lu do cadzu le bisli li'u
I express [quote] you walk-on the ice [unquote].
I say, “You walk on the ice.”

What is the implicit quantifier of the quotation

lu do cadzu le bisli li'u? Surely not ro. If ro were supplied explicitly, thus:
mi cusku ro lu do cadzu le bisli li'u
I express all-of [quote] you walk-on the ice [unquote].

the meaning would be something like “I say every occurrence of the sentence 'You walk on the ice'”. Of course I don't say every occurrence of it, only some occurrences. One might suppose that Example means that I express exactly one occurrence, but it is more Lojbanic to leave the number unspecified, as with other sumti. We can say definitely, however, that I say it at least once.

The Lojban cmavo meaning “at least” is su'o, and if no ordinary number follows, su'o means “at least once”. (See Example for the use of su'o with an ordinary number). Therefore, the explicitly quantified version of Example is

mi cusku su'o lu do cadzu le bisli li'u
I express at-least-one-of [quote] you walk-on the ice [unquote].
I say one or more instances of “You walk on the ice”.
I say “You walk on the ice”.

If an explicit ordinary number such as re were to appear, it would have to convey an exact expression, so

mi cusku re lu do cadzu le bisli li'u
I express two-of [quote] you walk-on the ice [unquote].

means that I say the sentence exactly twice, neither more nor less.

Quantified descriptions

The following cmavo are discussed in this section:




Like other sumti, descriptions can be quantified. When a quantifier appears before a description, it has the same meaning as one appearing before a non-description sumti: it specifies how many things, of all those referred to by the description, are being talked about in this particular bridi. Suppose that context tells us that

le gerku refers to three dogs. Then we can say that exactly two of them are white as follows:
re le gerku cu blabi
Two-of the dogs are-white.
Two of the dogs are white.

When discussing descriptions, this ordinary quantifier is called an “outer quantifier”, since it appears outside the description. But there is another possible location for a quantifier: between the descriptor and the selbri. This quantifier is called an “inner quantifier”, and its meaning is quite different: it tells the listener how many objects the description selbri characterizes.

For example, the context of Example supposedly told us that

le gerku referred to some three specific dogs. This assumption can be made certain with the use of an explicit inner quantifier:
re le ci gerku cu blabi
Two-of the three dogs are-white.
Two of the three dogs are white.

(As explained in the discussion of Example , simple numbers like those in Example must be exact: it therefore follows that the third dog cannot be white.)

You may also specify an explicit inner quantifier and leave the outer quantifier implicit:

le ci gerku cu blabi
The three dogs are-white.
The three dogs are white.

There are rules for each of the 11 descriptors specifying what the implicit values for the inner and outer quantifiers are. They are meant to provide sensible default values when context is absent, not necessarily to prescribe hard and fast rules. The following table lists the implicit values: <tab class=wikitable header=true>le: ro le su'o all of the at-least-one described aslo: su'o lo ro at least one of all of those which really arela: ro la su'o all of the at least one namedlei: pisu'o lei su'o some part of the mass of the at-least-one described asloi: pisu'o loi ro some part of the mass of all those that really arelai: pisu'o lai su'o some part of the mass of the at-least-one namedle'i: piro le'i su'o the whole of the set of the at-least-one described aslo'i: piro lo'i ro the whole of the set of all those that really arela'i: piro la'i su'o the whole of the set of the at-least-one namedle'e: ro le'e su'o all the stereotypes of the at-least-one described aslo'e: su'o lo'e ro at least one of the types of all those that really are </tab> When examined for the first time, this table looks dreadfully arbitrary. In fact, there are quite a few regularities in it. First of all, the la-series (that is, the descriptors la, lai, and la'i) and the le-series (that is, the descriptors le, lei, le'i, and le'e) always have corresponding implicit quantifiers, so we may subsume the la-series under the le-series for the rest of this discussion: “le-series cmavo” will refer to both the le-series proper and to the la-series.

The rule for the inner quantifier is very simple: the lo-series cmavo (namely, lo, loi, lo'i, and lo'e) all have an implicit inner quantifier of ro, whereas the le-series cmavo all have an implicit inner quantifier of su'o.

Why? Because lo-series descriptors always refer to all of the things which really fit into the x1 place of the selbri. They are not restricted by the speaker's intention. Descriptors of the le-series, however, are so restricted, and therefore talk about some number, definite or indefinite, of objects the speaker has in mind – but never less than one.

Understanding the implicit outer quantifier requires rules of greater subtlety. In the case of mass and set descriptors, a single rule suffices for each: reference to a mass is implicitly a reference to some part of the mass; reference to a set is implicitly a reference to the whole set. Masses and sets are inherently singular objects: it makes no sense to talk about two distinct masses with the same components, or two distinct sets with the same members. Therefore, the largest possible outer quantifier for either a set description or a mass description is piro, the whole of it.

(Pedantically, it is possible that the mass of water molecules composing an ice cube might be thought of as different from the same mass of water molecules in liquid form, in which case we might talk about

re lei djacu, two masses of the water-bits I have in mind.)

Why “pi-”? It is the Lojban cmavo for the decimal point. Just as

pimu means “.5”, and when used as a quantifier specifies a portion consisting of five tenths of a thing, piro means a portion consisting of the all-ness – the entirety – of a thing. Similarly, pisu'o specifies a portion consisting of at least one part of a thing, i.e. some of it.

Smaller quantifiers are possible for sets, and refer to subsets. Thus

pimu le'i nanmu is a subset of the set of men I have in mind; we don't know precisely which elements make up this subset, but it must have half the size of the full set. This is the best way to say “half of the men”; saying
pimu le nanmu would give us a half-portion of one of them instead! Of course, the result of
pimu le'i nanmu is still a set; if you need to refer to the individuals of the subset, you must say so (see lu'a in

Section 8.9).

The case of outer quantifiers for individual descriptors (including le, lo, la, and the typical descriptors le'e and lo'e) is special. When we refer to specific individuals with le, we mean to refer to all of those we have in mind, so ro is appropriate as the implicit quantifier, just as it is appropriate for do. Reference to non-specific individuals with lo, however, is typically to only some of the objects which can be correctly described, and so su'o is the appropriate implicit quantifier, just as for quotations.

From the English-speaking point of view, the difference in structure between the following example using le:

[ro] le ci gerku cu blabi
[All-of] those-described-as three dogs are-white.
The three dogs are white.

and the corresponding form with lo:

ci lo [ro] gerku cu blabi
Three-of those-which-are [all] dogs are-white.
Three dogs are white.

looks very peculiar. Why is the number ci found as an inner quantifier in Example and as an outer quantifier in Example ? The number of dogs is the same in either case. The answer is that the ci in Example is part of the specification: it tells us the actual number of dogs in the group that the speaker has in mind. In Example , however, the dogs referred to by

... lo gerku are all the dogs that exist: the outer quantifier then restricts the number to three; which three, we cannot tell. The implicit quantifiers are chosen to avoid claiming too much or too little: in the case of le, the implicit outer quantifier ro says that each of the dogs in the restricted group is white; in the case of lo, the implicit inner quantifier simply says that three dogs, chosen from the group of all the dogs there are, are white.

Using exact numbers as inner quantifiers in lo-series descriptions is dangerous, because you are stating that exactly that many things exist which really fit the description. So examples like

[so'o] lo ci gerku cu blabi
[some-of] those-which-really-are three dogs are-white

are semantically anomalous; Example claims that some dog (or dogs) is white, but also that there are just three dogs in the universe!

Nevertheless, inner quantifiers are permitted on lo descriptors for consistency's sake, and may occasionally be useful.

Note that the inner quantifier of le, even when exact, need not be truthful:

le ci nanmu means “what I describe as three men”, not “three of what I describe as men”. This follows from the rule that what is described by a le description represents the speaker's viewpoint rather than the objective way things are.

Indefinite descriptions

By a quirk of Lojban syntax, it is possible to omit the descriptor lo, but never any other descriptor, from a description like that of Example ; namely, one which has an explicit outer quantifier but no explicit inner quantifier. The following example:

ci gerku [ku] cu blabi
Three dogs are white.

is equivalent in meaning to Example . Even though the descriptor is not present, the elidable terminator ku may still be used. The name “indefinite description” for this syntactic form is historically based: of course, it is no more and no less indefinite than its counterpart with an explicit lo. Indefinite descriptions were introduced into the language in order to imitate the syntax of English and other natural languages.

Indefinite descriptions must fit this mold exactly: there is no way to make one which does not have an explicit outer quantifier (thus

*gerku cu blabi is ungrammatical), or which has an explicit inner quantifier (thus
*reboi ci gerku cu blabi is also ungrammatical –
re ci gerku cu blabi is fine, but means “23 dogs are white”).

Note: Example also contains an indefinite description, namely

su'o ci cutci; another version of that example using an explicit lo would be:
mi ponse su'o ci lo cutci
I possess at-least three things-which-really-are shoes
I own three (or more) shoes.

sumti-based descriptions

As stated in Section 8.1, most descriptions consist of just a descriptor and a selbri. (In this chapter, the selbri have always been single gismu, but of course any selbri, however complex, can be employed in a description. The syntax and semantics of selbri are explained in Chapter 6.) In the intervening sections, inner and outer quantifiers have been added to the syntax. Now it is time to discuss a description of a radically different kind: the sumti-based description.

A sumti-based description has a sumti where the selbri would normally be, and the inner quantifier is required – it cannot be implicit. An outer quantifier is permitted but not required.

A full theory of sumti-based descriptions has yet to be worked out. One common case, however, is well understood. Compare the following:


re do cu nanmu
Two-of you are-men.
le re do cu nanmu
The two-of you are men.Example simply specifies that of the group of listeners, size unknown, two are men. Example , which has the sumti-based description
le re do, says that of the two listeners, all (the implicit outer quantifier ro) are men. So in effect the inner quantifier re gives the number of individuals which the inner sumti

do refers to.

Here is another group of examples:

re le ci cribe cu bunre
Two-of the three bears are-brown.
le re le ci cribe cu bunre
The two-of the three bears are-brown.
pa le re le ci cribe cu bunre
One-of the two-of the three bears are-brown.

In each case,

le ci cribe restricts the bears (or alleged bears) being talked of to some group of three which the speaker has in mind. Example says that two of them (which two is not stated) are brown. Example says that a specific pair of them are brown. Example says that of a specific pair chosen from the original three, one or the other of that pair is brown.

sumti qualifiers

The following cmavo are discussed in this section:


Well, that's quite a list of cmavo. What are they all about?

The above cmavo and compound cmavo are called the “sumti qualifiers”. All of them are either single cmavo of selma'o LAhE, or else compound cmavo involving a scalar negation cmavo of selma'o NAhE immediately followed by bo of selma'o BO. Syntactically, you can prefix a sumti qualifier to any sumti and produce another simple sumti. (You may need to add the elidable terminator lu'u to show where the qualified sumti ends.)

Semantically, sumti qualifiers represent short forms of certain common special cases. Suppose you want to say “I see 'The Red Pony'”, where “The Red Pony” is the title of a book. How about:

mi viska lu le xunre cmaxirma li'u
I see [quote] the red small-horse [unquote].

But Example doesn't work: it says that you see a piece of text “The Red Pony”. That might be all right if you were looking at the cover of the book, where the words “The Red Pony” are presumably written. (More precisely, where the words

le xunre cmaxirma are written – but we may suppose the book has been translated into Lojban.)

What you really want to say is:

mi viska le selsinxa be lu le xunre cmaxirma li'u
I see the thing-represented-by [quote] the red small-horse [unquote].

The x2 place of

selsinxa (the x1 place of sinxa) is a sign or symbol, and the x1 place of
selsinxa (the x2 place of sinxa) is the thing represented by the sign. Example allows us to use a symbol (namely the title of a book) to represent the thing it is a symbol of (namely the book itself).

This operation turns out to be needed often enough that it's useful to be able to say:

mi viska la'e lu le xunre cmaxirma li'u [lu'u]
I see the-referent-of [quote] the red small-horse [unquote].

}} So when la'e is prefixed to a sumti referring to a symbol, it produces a sumti referring to the referent of that symbol. (In computer jargon, la'e dereferences a pointer.)

By introducing a sumti qualifier, we correct a false sentence ( Example ), which too closely resembles its literal English equivalent, into a true sentence ( Example ), without having to change it overmuch; in particular, the structure remains the same. Most of the uses of sumti qualifiers are of this general kind.

The sumti qualifier lu'e provides the converse operation: it can be prefixed to a sumti referring to some thing to produce a sumti referring to a sign or symbol for the thing. For example,


mi pu cusku lu'e le vi cukta
I [past] express a-symbol-for the nearby book.
I said the title of this book.

The equivalent form not using a sumti qualifier would be:

mi pu cusku le sinxa be le vi cukta
I [past] express the symbol-for the nearby book.

which is equivalent to Example , but longer.

The other sumti qualifiers follow the same rules. The cmavo tu'a is used in forming abstractions, and is explained more fully in Section 16.10. The triplet lu'a, lu'i, and lu'o convert between individuals, sets, and masses; vu'i belongs to this group as well, but creates a sequence, which is similar to a set but has a definite order. (The set of John and Charles is the same as the set of Charles and John, but the sequences are different.) Here are some examples:

mi troci tu'a le vorme
I try some-abstraction-about the door.
I try (to open) the door.

Example might mean that I try to do something else involving the door; the form is deliberately vague.

Most of the following examples make use of the cmavo ri, belonging to selma'o KOhA. This cmavo means “the thing last mentioned”; it is equivalent to repeating the immediately previous sumti (but in its original context). It is explained in more detail in Section 10.5.

lo'i ratcu cu barda .iku'i lu'a ri cmalu
The-set-of rats is-large. But some-members-of it-last-mentioned is-small.
The set of rats is large, but some of its members are small.
lo ratcu cu cmalu .iku'i lu'i ri barda
Some rats are-small. But the-set-of them-last-mentioned is-large.
Some rats are small, but the set of rats is large.
mi ce do girzu .i lu'o ri gunma .i vu'i ri porsi
I in-a-set-with you are-a-set. The-mass-of it-last-mentioned is-a-mass. The-sequence-of it-last-mentioned is-a-sequence
The set of you and me is a set. The mass of you and me is a mass. The sequence of you and me is a sequence.

(Yes, I know these examples are a bit silly. This set was introduced for completeness, and practical examples are as yet hard to come by.)

Finally, the four sumti qualifiers formed from a cmavo of NAhE and bo are all concerned with negation, which is discussed in detail in Chapter ELG-ERROR in Template:Lch. Here are a few examples of negation sumti qualifiers:

mi viska na'ebo le gerku
I see something-other-than the dog.

This compound,

na'ebo, is the most common of the four negation sumti qualifiers. The others usually only make sense in the context of repeating, with modifications, something already referred to:
mi nelci loi glare cidja .ije do nelci to'ebo ri .ije la djein. nelci no'ebo ra
I like part-of-the-mass-of hot-type-of food. And you like the-opposite-of the-last-mentioned. And Jane likes the-neutral-value-of something-mentioned.
I like hot food, and you like cold food, and Jane likes lukewarm food.

(In Example , the sumti ra refers to some previously mentioned sumti other than that referred to by ri. We cannot use ri here, because it would signify

la djein., that being the most recent sumti available to ri. See more detailed explanations in Section 10.5.)

The syntax of vocative phrases

Vocative phrases are not sumti, but are explained in this chapter because their syntax is very similar to that of sumti. Grammatically, a vocative phrase is one of the so-called “free modifiers” of Lojban, along with subscripts, parentheses, and various other constructs explained in Chapter ELG-ERROR in Template:Lch. They can be placed after many, but not all, constructions of the grammar: in general, after any elidable terminator (which, however, must not then be elided!), at the beginnings and ends of sentences, and in many other places.

The purpose of a vocative phrase is to indicate who is being addressed, or to indicate to that person that he or she ought to be listening. A vocative phrase begins with a cmavo of selma'o COI or DOI, all of which are explained in more detail in Section . Sometimes that is all there is to the phrase:


In these cases, the person being addressed is obvious from the context. However, a vocative word (more precisely, one or more cmavo of COI, possibly followed by doi, or else just doi by itself) can be followed by one of several kinds of phrases, all of which are intended to indicate the addressee. The most common case is a name:

coi. djan.
Hello, John.

A pause is required (for morphological reasons) between a member of COI and a name. You can use doi instead of a pause:

coi doi djan.
Hello, John.

means exactly the same thing and does not require a pause. Using doi by itself is like just saying someone's name to attract his or her attention:

doi djan.

In place of a name, a description may appear, lacking its descriptor, which is understood to be le:

coi xunre pastu nixli
Hello, (red-type-of dress)-type-of girl.
Hello, girl with the red dress!

The listener need not really be a

xunre pastu nixli, as long as she understands herself correctly from the description. (Actually, only a bare selbri can appear; explicit quantifiers are forbidden in this form of vocative, so the implicit quantifiers
su'o le ro are in effect.)

Finally, a complete sumti may be used, the most general case.

co'o la bab. .e la noras.
Goodbye, Bob and Nora.

Example is thus the same as:

coi le xunre pastu nixli
Hello, the-one-described-as red-dress girl!

and Example is the same as:

doi la djan.
The-one-named John!

Finally, the elidable terminator for vocative phrases is do'u (of selma'o DOhU), which is rarely needed except when a simple vocative word is being placed somewhere within a bridi. It may also be required when a vocative is placed between a sumti and its relative clause, or when there are a sequence of so-called “free modifiers” (vocatives, subscripts, utterance ordinals – See Chapter ELG-ERROR in Template:Lch – metalinguistic comments – See Section 18.55 – or reciprocals – seeChapter ELG-ERROR in Template:Lch) which must be properly separated.

The meaning of a vocative phrase that is within a sentence is not affected by its position in the sentence: thus Example and Example mean the same thing:

doi djan. ko klama mi
John, come to me!
ko klama mi doi djan.
Come to me, John!

As usual for this chapter, the full syntax of vocative phrases has not been explained: relative clauses, discussed in Chapter 12, make for more possibilities.

Lojban names

Names have been used freely as sumti throughout this chapter without too much explanation. The time for the explanation has now come.

First of all, there are two different kinds of things usually called “names” when talking about Lojban. The naming predicates of Section 8.1 are just ordinary predicates which are being used in a special sense. In addition, though, there is a class of Lojban words which are used only to name things: these can be recognized by the fact that they end in a consonant followed by a pause. Some examples:

djan. meris. djein. .alis.
John. Mary. Jane. Alice.

(Note that .alis. begins as well as ends with a pause, because all Lojban words beginning with a vowel must be preceded by a pause. See Chapter 5 for more information.)

Names of this kind have two basic uses in Lojban: when used in a vocative phrase (see Section 8.10) they indicate who the listener is or should be. When used with a descriptor of selma'o LA, namely la, lai, or la'i, they form sumti which refer to the persons or things known by the name.

la djonz. klama le zarci
Jones goes to-the store.
The Joneses go to-the store.
lai djonz. klama le zarci
The-mass-of Joneses go to-the store.
The Joneses go to the store.

In Example , the significance is that all the persons (perhaps only one) I mean to refer to by the name djonz. are going to the store. In Example , the Joneses are massified, and only some part of them needs to be going. Of course, by djonz. I can mean whomever I want: that person need not use the name djonz. at all.

The sumti in Example and Example operate exactly like the similar uses of la and lai in Example and Example respectively. The only difference is that these descriptors are followed by Lojban name-words. And in fact, the only difference between descriptors of selma'o LA (these three) and of selma'o LE (all the other descriptors) is that the former can be followed by name-words, whereas the latter cannot.

There are certain limitations on the form of name-words in Lojban. In particular, they cannot contain the letter-sequences (or sound-sequences) la, lai, or doi unless a consonant immediately precedes within the name. Reciprocally, every name not preceded by la, lai, la'i, or doi must be preceded by a pause instead:

coi .djan.
Hello, John.
zo .djan. cmene mi
The-word “John” is-the-name-of me.
My name is John.

In Example and Example , .djan. appears with a pause before it as well as after it, because the preceding word is not one of the four special cases. These rules force names to always be separable from the general word-stream.

Unless some other rule prevents it (such as the rule that zo is always followed by a single word, which is quoted), multiple names may appear wherever one name is permitted, each with its terminating pause:

doi djan. pol. djonz. le bloti cu klama fi la niuport. niuz.
John Paul Jones, the boat comes (to somewhere) from Newport News.

A name may not contain any consonant combination that is illegal in Lojban words generally: the “impermissible consonant clusters” of Lojban morphology (explained in Section 2.3). Thus djeimz. is not a valid version of “James” (because mz is invalid): djeimyz will suffice. Similarly, la may be replaced by ly, lai by

ly'i, doi by do'i or dai. Here are a few examples:

<tab class=wikitable header=true> Doyle *doi,l do'il or dai,l Lyra *lairas ly'iras Lottie *latis LYtis. or lotis. (American pronunciation) </tab>

Names may be borrowed from other languages or created arbitrarily. Another common practice is to use one or more rafsi, arranged to end with a consonant, to form a name: thus the rafsi loj- for logji (logical) and ban- for bangu (language) unite to form the name of this language:


When borrowing names from another language which end in a vowel, or when turning a Lojban brivla (all of which end in vowels) into a name, the vowel may be removed or an arbitrary consonant added. It is common (but not required) to use the consonants

s or n when borrowing vowel-final names from English; speakers of other languages may wish to use other consonant endings.

The implicit quantifier for name sumti of the form la followed by a name is su'o, just as for la followed by a selbri.

Pro-sumti summary

The Lojban pro-sumti are the cmavo of selma'o KOhA. They fall into several classes: personal, definable, quantificational, reflexive, back-counting, indefinite, demonstrative, metalinguistic, relative, question. More details are given in Chapter 10; this section mostly duplicates information found there, but adds material on the implicit quantifier of each pro-sumti.

The following examples illustrate each of the classes. Unless otherwise noted below, the implicit quantification for pro-sumti is ro (all). In the case of pro-sumti which refer to other sumti, the ro signifies “all of those referred to by the other sumti”: thus it is possible to restrict, but not to extend, the quantification of the other sumti.

Personal pro-sumti ( mi, do, mi'o, mi'a, ma'a, do'o, ko) refer to the speaker or the listener or both, with or without third parties:

mi prami do
I love you.

The personal pro-sumti may be interpreted in context as either representing individuals or masses, so the implicit quantifier may be pisu'o rather than ro: in particular, mi'o, mi'a, ma'a, and do'o specifically represent mass combinations of the individuals (you and I, I and others, you and I and others, you and others) that make them up.

Definable pro-sumti ( ko'a, ko'e, ko'i, ko'o, ko'u, fo'a, fo'e, fo'i, fo'o, fo'u) refer to whatever the speaker has explicitly made them refer to. This reference is accomplished with goi (of selma'o GOI), which means “defined-as”.

le cribe goi ko'a cu xekri .i ko'a citka le smacu
The bear defined-as it-1 is-black. It-1 eats the mouse.

Quantificational pro-sumti ( da, de, di) are used as variables in bridi involving predicate logic:

ro da poi prenu cu prami pa de poi finpe
All somethings-1 which-are persons love one something-2 which-is a-fish.
All persons love a fish (each his/her own).

(This is not the same as “All persons love a certain fish”; the difference between the two is one of quantifier order.) The implicit quantification rules for quantificational pro-sumti are particular to them, and are discussed in detail in Chapter 17. Roughly speaking, the quantifier is su'o (at least one) when the pro-sumti is first used, and ro (all) thereafter.

Reflexive pro-sumti ( vo'a, vo'e, vo'i, vo'o, vo'u) refer to the same referents as sumti filling other places in the same bridi, with the effect that the same thing is referred to twice:

le cribe cu batci vo'a
The bear bites what-is-in-the-x1-place.
The bear bites itself.

Back-counting pro-sumti ( ri, ra, ru) refer to the referents of previous sumti counted backwards from the pro-sumti:

mi klama la frankfurt. ri
I go to-Frankfurt from-the-referent-of-the-last-sumti
I go from Frankfurt to Frankfurt (by some unstated route).

Indefinite pro-sumti ( zo'e, zu'i, zi'o) refer to something which is unspecified:

mi klama la frankfurt. zo'e zo'e zo'e
I go to-Frankfurt from-unspecified via-unspecified by-means-unspecified.

The implicit quantifier for indefinite pro-sumti is, well, indefinite. It might be ro (all) or su'o (at least one) or conceivably even no (none), though no would require a very odd context indeed.

Demonstrative pro-sumti ( ti, ta, tu) refer to things pointed at by the speaker, or when pointing is not possible, to things near or far from the speaker:

ko muvgau ti ta tu
You [imperative] move this-thing from-that-nearby-place to-that-further-away-place.
Move this from there to over there!

Metalinguistic pro-sumti ( di'u, de'u, da'u, di'e, de'e, da'e, dei, do'i) refer to spoken or written utterances, either preceding, following, or the same as the current utterance.

li re su'i re du li vo .i la'e di'u jetnu
The-number two plus two equals the-number four. The-referent-of the-previous-utterance is-true.

The implicit quantifier for metalinguistic pro-sumti is su'o (at least one), because they are considered analogous to lo descriptions: they refer to things which really are previous, current, or following utterances.

The relative pro-sumti ( ke'a) is used within relative clauses (See Chapter 12 for a discussion of relative clauses) to refer to whatever sumti the relative clause is attached to.

mi viska le mlatu ku poi zo'e zbasu ke'a loi slasi
I see the cat(s) such-that something-unspecified makes it/them (the cats) from-a-mass-of plastic.
I see the cat(s) made of plastic.

The question pro-sumti ( ma) is used to ask questions which request the listener to supply a sumti which will make the question into a truth:

do klama ma
You go to-what-sumti?
Where are you going?

The implicit quantifier for the question pro-sumti is su'o (at least one), because the listener is only being asked to supply a single answer, not all correct answers.

In addition, sequences of lerfu words (of selma'o BY and related selma'o) can also be used as definable pro-sumti.

Quotation summary

There are four kinds of quotation in Lojban: text quotation, words quotation, single-word quotation, non-Lojban quotation. More information is provided in Chapter ELG-ERROR in Template:Lch.

Text quotations are preceded by lu and followed by li'u, and are an essential part of the surrounding text: they must be grammatical Lojban texts.

mi cusku lu mi'e djan. li'u
I say the-text [quote] I-am John [unquote].
I say “I'm John”.

Words quotations are quotations of one or more Lojban words. The words need not mean anything, but they must be morphologically valid so that the end of the quotation can be discerned.

mi cusku lo'u li mi le'u
I say the-words [quote] li mi [unquote].
I say “li mi”.

Note that the translation of Example does not translate the Lojban words, because they are not presumed to have any meaning (in fact, they are ungrammatical).

Single-word quotation quotes a single Lojban word. Compound cmavo are not allowed.

mi cusku zo .ai
I say the-word ai.

Non-Lojban quotation can quote anything, Lojban or not, even non-speech such as drum talk, whistle words, music, or belching. A Lojban word which does not appear within the quotation is used before and after it to set it off from the surrounding Lojban text.

mi cusku zoi kuot. I'm John .kuot
I say “I'm John”.

The implicit quantifier for all types of quotation is su'o (at least one), because quotations are analogous to lo descriptions: they refer to things which actually are words or sequences of words.

Number summary

The sumti which refer to numbers consist of the cmavo li (of selma'o LI) followed by an arbitrary Lojban mekso, or mathematical expression. This can be anything from a simple number up to the most complicated combination of numbers, variables, operators, and so on. Much more information on numbers is given in Chapter ELG-ERROR in Template:Lch. Here are a few examples of increasing complexity:

li vo
the-number four
li re su'i re
the-number two plus two
2 + 2
li .abu bopi'i xy. bote'a re su'i by. bopi'i xy. su'i cy.
the-number a times x to-power 2 plus b times x plus c
ax2 + bx + c

An alternative to li is me'o, also of selma'o LI. Number expressions beginning with me'o refer to the actual expression, rather than its value. Thus Example and Example above have the same meaning, the number four, whereas

me'o vo
the-expression four


me'o re su'i re
the-expression two plus two

refer to different pieces of text.

The implicit quantifier for numbers and mathematical expressions is su'o, because these sumti are analogous to lo descriptions: they refer to things which actually are numbers or pieces of text. In the case of numbers (with li), this is a distinction without a difference, as there is only one number which is 4; but there are many texts “4”, as many as there are documents in which that numeral appears.

Anaphora. Pronouns and reference verbs

What are pro-sumti and pro-bridi? What are they for?

Speakers of Lojban, like speakers of other languages, require mechanisms of abbreviation. If every time we referred to something, we had to express a complete description of it, life would be too short to say what we have to say. In English, we have words called “pronouns” which allow us to replace nouns or noun phrases with shorter terms. An English with no pronouns might look something like this:

Speakers of Lojban, like speakers of other languages, require mechanisms of abbreviation. If every time speakers of Lojban referred to a thing to which speakers of Lojban refer, speakers of Lojban had to express a complete description of what speakers of Lojban referred to, life would be too short to say what speakers of Lojban have to say.

Speakers of this kind of English would get mightily sick of talking. Furthermore, there are uses of pronouns in English which are independent of abbreviation. There is all the difference in the world between:

John picked up a stick and shook it.


John picked up a stick and shook a stick.Example does not imply that the two sticks are necessarily the same, whereas Example requires that they are.

In Lojban, we have sumti rather than nouns, so our equivalent of pronouns are called by the hybrid term “pro-sumti”. A purely Lojban term would be

sumti cmavo: all of the pro-sumti are cmavo belonging to selma'o KOhA. In exactly the same way, Lojban has a group of cmavo (belonging to selma'o GOhA) which serve as selbri or full bridi. These may be called “pro-bridi” or
bridi cmavo. This chapter explains the uses of all the members of selma'o KOhA and GOhA. They fall into a number of groups, known as series: thus, in selma'o KOhA, we have among others the mi-series, the ko'a-series, the da-series, and so on. In each section, a series of pro-sumti is explained, and if there is a corresponding series of pro-bridi, it is explained and contrasted. Many pro-sumti series don't have pro-bridi analogues, however.

A few technical terms: The term “referent” means the thing to which a pro-sumti (by extension, a pro-bridi) refers. If the speaker of a sentence is James, then the referent of the word “I” is James. On the other hand, the term “antecedent” refers to a piece of language which a pro-sumti (or pro-bridi) implicitly repeats. In

John loves himself

the antecedent of “himself” is “John”; not the person, but a piece of text (a name, in this case). John, the person, would be the referent of “himself”. Not all pro-sumti or pro-bridi have antecedents, but all of them have referents.

Personal pro-sumti: the mi-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning mi KOhA mi-series I, me do KOhA mi-series you mi'o KOhA mi-series you and I mi'a KOhA mi-series I and others, we but not you ma'a KOhA mi-series you and I and others do'o KOhA mi-series you and others ko KOhA mi-series you-imperative </tab>

The mi-series of pro-sumti refer to the speaker, the listener, and others in various combinations. mi refers to the speaker and perhaps others for whom the speaker speaks; it may be a Lojbanic mass. do refers to the listener or listeners. Neither mi nor do is specific about the number of persons referred to; for example, the foreman of a jury may refer to the members of the jury as mi, since in speaking officially he represents all of them.

The referents of mi and do are usually obvious from the context, but may be assigned by the vocative words of selma'o COI, explained in Section . The vocative mi'e assigns mi, whereas all of the other vocatives assign do.

mi'e djan. doi frank. mi cusku lu mi bajra li'u do
I-am John, O Frank, I express [quote] I run [unquote] to-you
I am John, Frank; I tell you “I run”.

The cmavo mi'o, mi'a, ma'a, and do'o express various combinations of the speaker and/or the listener and/or other people:

  • mi'o includes only the speaker and the listener but no one else;
  • mi'a includes the speaker and others but excludes the listener;
  • do'o includes the listener and others but excludes the speaker;
  • ma'a includes all three: speaker, listener, others.

All of these pro-sumti represent masses. For example, mi'o is the same as

mi joi do, the mass of me and you considered jointly.
  In English, “we” can mean mi or mi'o or mi'a or even 

ma'a, and English-speakers often suffer because they cannot easily distinguish mi'o from mi'a:

We're going to the store.

Does this include the listener or not? There's no way to be sure.

Finally, the cmavo ko is logically equivalent to do; its referent is the listener. However, its use alters an assertion about the listener into a command to the listener to make the assertion true:

do klama le zarci
You go to-the store.


ko klama le zarci
You [imperative] go to-the store.
Make “you go to the store” true!
Go to the store!

In English, the subject of a command is omitted, but in Lojban, the word ko must be used. However, ko does not have to appear in the x1 place:

mi viska ko
I see you [imperative]

Make “I see you” true!

Be seen by me!

In Example , it is necessary to make the verb passive in English in order to convey the effect of ko in the x2 place. Indeed, ko does not even have to be a sumti of the main bridi:

mi viska le prenu poi prami ko
I see the person that loves you [imperative]

Make “I see the person that loves you” true!

Be such that the person who loves you is seen by me!
Show me the person who loves you!

As mentioned in Section , some pro-sumti series have corresponding pro-bridi series. However, there is no equivalent of the mi-series among pro-bridi, since a person isn't a relationship.

Demonstrative pro-sumti: the ti-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ti KOhA ti-series this here, a nearby object ta KOhA ti-series that there, a medium-distant object tu KOhA ti-series that yonder, a far-distant object </tab>

It is often useful to refer to things by pointing to them or by some related non-linguistic mechanism. In English, the words “this” and “that” serve this function among others: “this” refers to something pointed at that is near the speaker, and “that” refers to something further away. The Lojban pro-sumti of the ti-series serve the same functions, but more narrowly. The cmavo ti, ta, and tu provide only the pointing function of “this” and “that”; they are not used to refer to things that cannot be pointed at.

There are three pro-sumti of the ti-series rather than just two because it is often useful to distinguish between objects that are at more than two different distances. Japanese, among other languages, regularly does this. Until the 16th century, English did too; the pronoun “that” referred to something at a medium distance from the speaker, and the now-archaic pronoun “yon” to something far away.

In conversation, there is a special rule about ta and tu that is often helpful in interpreting them. When used contrastingly, ta refers to something that is near the listener, whereas tu refers to something far from both speaker and listener. This makes for a parallelism between ti and mi, and ta and do, that is convenient when pointing is not possible; for example, when talking by telephone. In written text, on the other hand, the meaning of the ti-series is inherently vague; is the writer to be taken as pointing to something, and if so, to what? In all cases, what counts as “near” and “far away” is relative to the current situation.

It is important to distinguish between the English pronoun “this” and the English adjective “this” as in “this boat”. The latter is not represented in Lojban by ti:

le ti bloti
the this boat

does not mean “this boat” but rather “this one's boat”, “the boat associated with this thing”, as explained in Section 12.6. A correct Lojban translation of Example is

le vi bloti
the here boat
the nearby boat

using a spatial tense before the selbri bloti to express that the boat is near the speaker. (Tenses are explained in full in Chapter 14.) Another correct translation would be:

ti noi bloti
this-thing which-incidentally is-a-boat

There are no demonstrative pro-bridi to correspond to the ti-series: you can't point to a relationship.

Utterance pro-sumti: the di'u-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning di'u KOhA di'u-series the previous utterance de'u KOhA di'u-series an earlier utterance da'u KOhA di'u-series a much earlier utterance di'e KOhA di'u-series the next utterance de'e KOhA di'u-series a later utterance da'e KOhA di'u-series a much later utterance dei KOhA di'u-series this very utterance do'i KOhA di'u-series some utterance </tab>

The cmavo of the di'u-series enable us to talk about things that have been, are being, or will be said. In English, it is normal to use “this” and “that” for this (indeed, the immediately preceding “this” is an example of such a usage):

You don't like cats.

That is untrue.

Here “that” does not refer to something that can be pointed to, but to the preceding sentence “You don't like cats”. In Lojban, therefore, Example is rendered:

do na nelci loi mlatu .i di'u jitfa jufra
You (Not!) like the-mass-of cats. The-previous-utterance is-a-false-sentence.

Using ta instead of di'u would cause the listener to look around to see what the speaker of the second sentence was physically pointing to.

As with ti, ta, and tu, the cmavo of the di'u-series come in threes: a close utterance, a medium-distance utterance, and a distant utterance, either in the past or in the future. It turned out to be impossible to use the i/ a/ u vowel convention of the demonstratives in Section 10.2 without causing collisions with other cmavo, and so the di'u-series has a unique i/ e/ a convention in the first vowel of the cmavo.

Most references in speech are to the past (what has already been said), so di'e, de'e, and da'e are not very useful when speaking. In writing, they are frequently handy:

la saimn. cusku di'e
Simon expresses the-following-utterance.
Simon says:

Example would typically be followed by a quotation. Note that although presumably the quotation is of something Simon has said in the past, the quotation utterance itself would appear after Example , and so di'e is appropriate.

The remaining two cmavo, dei and do'i, refer respectively to the very utterance that the speaker is uttering, and to some vague or unspecified utterance uttered by someone at some time:

dei jetnu jufra
This-utterance is-a-true-sentence.
What I am saying (at this moment) is true.
do'i jetnu jufra
Some-utterance is-a-true-sentence.
That's true (where “that” is not necessarily what was just said).

The cmavo of the di'u-series have a meaning that is relative to the context. The referent of dei in the current utterance is the same as the referent of di'u in the next utterance. The term “utterance” is used rather than “sentence” because the amount of speech or written text referred to by any of these words is vague. Often, a single bridi is intended, but longer utterances may be thus referred to.

Note one very common construction with di'u and the cmavo la'e (of selma'o LAhE; See Section 8.9) which precedes a sumti and means “the thing referred to by (the sumti)”:

mi prami la djein. .i mi nelci la'e di'u
I love Jane. And I like the-referent-of the-last-utterance.
I love Jane, and I like that.

The effect of

la'e di'u in Example is that the speaker likes, not the previous sentence, but rather the state of affairs referred to by the previous sentence, namely his loving Jane. This cmavo compound is often written as a single word: la'edi'u. It is important not to mix up

di'u and la'edi'u, or the wrong meaning will generally result:

mi prami la djein. .i mi nelci di'u
I love Jane. And I like the-last-utterance.

says that the speaker likes one of his own sentences.

There are no pro-bridi corresponding to the di'u-series.

Assignable pro-sumti and pro-bridi: the ko'a-series and the broda-series

The following cmavo and gismu are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ko'a KOhA KO'a-series it-1 ko'e KOhA KO'a-series it-2 ko'i KOhA KO'a-series it-3 ko'o KOhA KO'a-series it-4 ko'u KOhA KO'a-series it-5 fo'a KOhA KO'a-series it-6 fo'e KOhA KO'a-series it-7 fo'i KOhA KO'a-series it-8 fo'o KOhA KO'a-series it-9 fo'u KOhA KO'a-series it-10 broda BRIVLA broda-series is-thing-1 brode BRIVLA broda-series is-thing-2 brodi BRIVLA broda-series is-thing-3 brodo BRIVLA broda-series is-thing-4 brodu BRIVLA broda-series is-thing-5 goi GOI pro-sumti assignment cei CEI pro-bridi assignment </tab>

The discussion of personal pro-sumti in Section 10.1 may have seemed incomplete. In English, the personal pronouns include not only “I” and “you” but also “he”, “she”, “it”, and “they”. Lojban does have equivalents of this latter group: in fact, it has more of them than English does. However, they are organized and used very differently.

There are ten cmavo in the ko'a-series, and they may be assigned freely to any sumti whatsoever. The English word “he” can refer only to males, “she” only to females (and ships and a few other things), “it” only to inanimate things, and “they” only to plurals; the cmavo of the ko'a-series have no restrictions at all. Therefore, it is almost impossible to guess from the context what ko'a-series cmavo might refer to if they are just used freely:

la .alis. klama le zarci .i ko'a blanu
Alice goes-to the store. It-1 is-blue.

The English gloss “it-1”, plus knowledge about the real world, would tend to make English-speakers believe that ko'a refers to the store; in other words, that its antecedent is

le zarci. To a Lojbanist, however,
la .alis. is just as likely an antecedent, in which case Example means that Alice, not the store, is blue.

To avoid this pitfall, Lojban employs special syntax, using the cmavo goi:

la .alis. klama le zarci .i ko'a goi la .alis. cu blanu
Alice goes-to the store. It-1, also-known-as Alice, is-blue.


goi la .alis. is a relative phrase (relative phrases are explained in Chapter 12). Semantically, it says that ko'a and
la .alis. refer to the same thing, and furthermore that this is true because ko'a is being defined as meaning
la .alis.. It is equally correct to say:
la .alis. klama le zarci .i la .alis. goi ko'a cu blanu
Alice goes-to the store. Alice, also-known-as it-1, is-blue.

in other words, goi is symmetrical. There is a terminator, ge'u (of selma'o GEhU), which is almost always elidable. The details are in Section 12.2.

The afterthought form of goi shown in Example and Example is probably most common in speech, where we do not know until part way through our utterance that we will want to refer to Alice again. In writing, though, ko'a may be assigned at the point where Alice is first mentioned. An example of this forethought form of goi is:

la .alis. goi ko'a klama le zarci .i ko'a cu blanu
Alice, also-known-as it-1, goes-to the store. It-1 is-blue.

Again, ko'a goi la .alis. would have been entirely acceptable in Example . This last form is reminiscent of legal jargon: “The party of the first part, hereafter known as Buyer, ...”.

Just as the ko'a-series of pro-sumti allows a substitute for a sumti which is long or complex, or which for some other reason we do not want to repeat, so the broda-series of pro-bridi allows a substitute for a selbri or even a whole bridi:

ti slasi je mlatu bo cidja lante gacri cei broda .i le crino broda cu barda .i le xunre broda cu cmalu
These are plastic cat-food can covers or thingies. The green thingy is large. The red thingy is small.

The pro-bridi broda has as its antecedent the selbri

slasi je mlatu bo cidja lante gacri. The cmavo cei performs the role of

goi in assigning broda to this long phrase, and broda can then be used just like any other brivla. (In fact, broda and its relatives actually are brivla: they are gismu in morphology, although they behave exactly like the members of selma'o GOhA. The reasons for using gismu rather than cmavo are buried in the Loglan Project's history.)

Note that pro-bridi are so called because, even though they have the grammar of selbri, their antecedents are whole bridi. In the following rather contrived example, the antecedent of brode is the whole bridi

mi klama le zarci:
mi klama cei brode le zarci .i do brode
I go-to (which-is claim-1) the store. You claim-1.
I go to the store. You, too.

In the second bridi,

do brode means
do klama le zarci, because brode carries the x2 sumti of
mi klama le zarci along with it. It also potentially carries the x1 sumti as well, but the explicit x1 sumti do overrides the mi of the antecedent bridi. Similarly, any tense or negation that is present in the antecedent is also carried, and can be overridden by explicit tense or negation cmavo on the pro-bridi. These rules hold for all pro-bridi that have antecedents.

Another use of broda and its relatives, without assignment, is as “sample gismu”:

broda ke brode brodi
a thing-1 type of (thing-2 type-of thing-3)

represents an abstract pattern, a certain kind of tanru. (Historically, this use was the original one.)

As is explained in Section 18.8, the words for Lojban letters, belonging to selma'o BY and certain related selma'o, are also usable as assignable pro-sumti. The main difference between letter pro-sumti and ko'a-series pro-sumti is that, in the absence of an explicit assignment, letters are taken to refer to the most recent name or description sumti beginning with the same letter:

mi viska le gerku .i gy. cusku zo arf.

I see the dog. D expresses the-word “Arf!”.

The Lojban word gerku begins with g, so the antecedent of gy., the cmavo for the letter g, must be

le gerku. In the English translation, we use the same principle to refer to the dog as “D”. Of course, in case of ambiguity, goi can be used to make an explicit assignment.

Furthermore, goi can even be used to assign a name:

le ninmu goi la sam. cu klama le zarci
The woman also-known-as Sam goes to-the store.
The woman, whom I'll call Sam, goes to the store.

This usage does not imply that the woman's name is Sam, or even that the speaker usually calls the woman “Sam”. “Sam” is simply a name chosen, as if at random, for use in the current context only.

Anaphoric pro-sumti and pro-bridi: the ri-series and the go'i-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ri KOhA ri-series (repeats last sumti) ra KOhA ri-series (repeats previous sumti) ru KOhA ri-series (repeats long-ago sumti)

go'i GOhA GO'i-series (repeats last bridi) go'a GOhA GO'i-series (repeats previous bridi) go'u GOhA GO'i-series (repeats long-ago bridi) go'e GOhA GO'i-series (repeats last-but-one bridi) go'o GOhA GO'i-series (repeats future bridi) nei GOhA GO'i-series (repeats current bridi) no'a GOhA GO'i-series (repeats outer bridi)

ra'o RAhO pro-cmavo update </tab>

The term “anaphora” literally means “repetition”, but is used in linguistics to refer to pronouns whose significance is the repetition of earlier words, namely their antecedents. Lojban provides three pro-sumti anaphora, ri, ra, and ru; and three corresponding pro-bridi anaphora, go'i, go'a, and go'u. These cmavo reveal the same vowel pattern as the ti-series, but the “distances” referred to are not physical distances, but distances from the anaphoric cmavo to its antecedent.

The cmavo ri is the simplest of these; it has the same referent as the last complete sumti appearing before the ri:

la .alis. sipna le ri kumfa
Alice sleeps-in the of-[repeat last sumti] room.
Alice sleeps in her room.

The ri in Example is equivalent to repeating the last sumti, which is

la .alis., so Example is equivalent to:
la .alis. sipna le la .alis. kumfa
Alice sleeps-in the of-Alice room.
Alice sleeps in Alice's room.

Note that ri does not repeat

le ri kumfa, because that sumti is not yet complete when ri appears. This prevents ri from getting entangled in paradoxes of self-reference. (There are plenty of other ways to do that!) Note also that sumti within other sumti, as in quotations, abstractions, and the like, are counted in the order of their beginnings; thus a lower level sumti like
la alis. in Example is considered to be more recent than a higher level sumti that contains it.

Certain sumti are ignored by ri; specifically, most of the other cmavo of KOhA, and the almost-grammatically-equivalent lerfu words of selma'o BY. It is simpler just to repeat these directly:

mi prami mi
I love me.
I love myself.

However, the cmavo of the ti-series can be picked up by ri, because you might have changed what you are pointing at, so repeating ti may not be effective. Likewise, ri itself (or rather its antecedent) can be repeated by a later ri; in fact, a string of ri cmavo with no other intervening sumti always all repeat the same sumti:

la djan. viska le tricu .i ri se jadni le ri jimca
John sees the tree. [repeat last] is-adorned-by the of-[repeat last] branch.
John sees the tree. It is adorned by its branches.

Here the second ri has as antecedent the first ri, which has as antecedent

le tricu. All three refer to the same thing: a tree.

To refer to the next-to-last sumti, the third-from-last sumti, and so on, ri may be subscripted (subscripts are explained in Section 18.49):

lo smuci .i lo forca .i la rik. pilno rixire .i la .alis. pilno riximu
A spoon. A fork. Rick uses [repeat next-to-last]. Alice uses [repeat fifth-from-last].


rixire, or “ri-sub-2”, skips
la rik. to reach
lo forca. In the same way,
riximu, or “ri-sub-5”, skips
la .alis.,
la rik., and
lo forca to reach
lo smuci. As can clearly be seen, this procedure is barely practicable in writing, and would break down totally in speech.

Therefore, the vaguer ra and ru are also provided. The cmavo ra repeats a recently used sumti, and ru one that was further back in the speech or text. The use of ra and ru forces the listener to guess at the referent, but makes life easier for the speaker. Can ra refer to the last sumti, like ri? The answer is no if ri has also been used. If ri has not been used, then ra might be the last sumti. Likewise, if ra has been used, then any use of ru would repeat a sumti earlier than the one ra is repeating. A more reasonable version of Example Example , but one that depends more on context, is:

lo smuci .i lo forca .i la rik. pilno ra .i la .alis. pilno ru
A spoon. A fork. Rick uses [some previous thing]. Alice uses [some more remote thing].

In Example , the use of ra tells us that something other than

la rik. is the antecedent;
lo forca is the nearest sumti, so it is probably the antecedent. Similarly, the antecedent of ru must be something even further back in the utterance than
lo forca, and
lo smuci is the obvious candidate.

The meaning of ri must be determined every time it is used. Since ra and ru are more vaguely defined, they may well retain the same meaning for a while, but the listener cannot count on this behavior. To make a permanent reference to something repeated by ri, ra, or ru, use goi and a ko'a-series cmavo:

la .alis. klama le zarci .i ri goi ko'a blanu
Alice goes-to the store. It-last-mentioned also-known-as it-1 is-blue.

allows the store to be referred to henceforth as ko'a without ambiguity. Example is equivalent to Example and eliminates any possibility of ko'a being interpreted by the listener as referring to Alice.

The cmavo go'i, go'a, and go'u follow exactly the same rules as ri, ra, and ru, except that they are pro-bridi, and therefore repeat bridi, not sumti – specifically, main sentence bridi. Any bridi that are embedded within other bridi, such as relative clauses or abstractions, are not counted. Like the cmavo of the broda-series, the cmavo of the go'i-series copy all sumti with them. This makes go'i by itself convenient for answering a question affirmatively, or for repeating the last bridi, possibly with new sumti:

xu zo djan. cmene do .i go'i

[True-false?] The-word “John” is-the-name of you? [repeat last bridi].

Is John your name? Yes.
mi klama le zarci .i do go'i
I go-to the store. You [repeat last bridi].
I go to the store. You, too.

Note that Example means the same as Example , but without the bother of assigning an actual broda-series word to the first bridi. For long-term reference, use

go'i cei broda or the like, analogously to
ri goi ko'a in Example .

The remaining four cmavo of the go'i-series are provided for convenience or for achieving special effects. The cmavo go'e means the same as

go'ixire: it repeats the last bridi but one. This is useful in conversation:
A: mi ba klama le zarci B: mi nelci le si'o mi go'i A: do go'e
A: I [future] go-to the store. B: I like the concept-of I [repeat last bridi]. A: You [repeat last bridi but one].
A: I am going to the store. B: I like the idea of my going. A: You'll go, too.

Here B's sentence repeats A's within an abstraction (explained in Chapter 16):

le si'o mi go'i means
le si'o mi klama le zarci. Why must B use the word mi explicitly to replace the x1 of
mi klama le zarci, even though it looks like mi is replacing mi? Because B's mi refers to B, whereas A's mi refers to A. If B said:
mi nelci le si'o go'i

that would mean:

I like the idea of your going to the store.

The repetition signalled by go'i is not literally of words, but of concepts. Finally, A repeats her own sentence, but with the x1 changed to do, meaning B. Note that in Example , the tense ba (future time) is carried along by both go'i and go'e.

Descriptions based on go'i-series cmavo can be very useful for repeating specific sumti of previous bridi:

le xekri mlatu cu klama le zarci .i le go'i cu cadzu le bisli
The black cat goes-to the store. That-described-as-the-x1-place-of [repeat last bridi] walks-on the ice.
The black cat goes to the store. It walks on the ice.

Here the go'i repeats

le xekri mlatu cu klama le zarci, and since le makes the x1 place into a description, and the x1 place of this bridi is
le xekri mlatu,
le go'i means
le xekri mlatu.

The cmavo go'o, nei, and no'a have been little used so far. They repeat respectively some future bridi, the current bridi, and the bridi that encloses the current bridi ( no'a, unlike the other members of the go'i- series, can repeat non-sentence bridi). Here are a few examples:

mi nupre le nu mi go'o .i ba dunda le djini le bersa .i ba dunda le zdani le tixnu
I promise the event-of I [repeat future bridi] [Future] give the money to-the son [Future] give the house to-the daughter
I promise to do the following: Give the money to my son. Give the house to my daughter.

(Note: The Lojban does not contain an equivalent of the my in the colloquial English; it leaves the fact that it is the speaker's son and daughter that are referred to implicit. To make the fact explicit, use

le bersa/tixnu be mi.)

For good examples of nei and no'a, we need nested bridi contexts:

mi se pluka le nu do pensi le nu nei kei pu le nu do zukte
I am-pleased-by the event-of (you think-about (the event-of [main bridi]) before the-event of (your acting).
I am pleased that you thought about whether I would be pleased (about ...) before you acted.
mi ba klama ca le nu do no'a
I [future] go [present] the event-of you [repeats outer bridi]
I will go when you do.

Finally, ra'o is a cmavo that can be appended to any go'i-series cmavo, or indeed any cmavo of selma'o GOhA, to signal that pro-sumti or pro-bridi cmavo in the antecedent are to be repeated literally and reinterpreted in their new context. Normally, any pro-sumti used within the antecedent of the pro-bridi keep their meanings intact. In the presence of ra'o, however, their meanings must be reinterpreted with reference to the new environment. If someone says to you:

mi ba lumci lemi karce
I will wash my car.

you might reply either:

mi go'i
I will wash your car.


mi go'i ra'o
I will wash my car.

The ra'o forces the second mi from the original bridi to mean the new speaker rather than the former speaker. This means that

go'e ra'o would be an acceptable alternative to
do go'e in B's statement in Example .

The anaphoric pro-sumti of this section can be used in quotations, but never refer to any of the supporting text outside the quotation, since speakers presumably do not know that they may be quoted by someone else.

However, a

ri- series or
go'a- series reference within a quotation can refer to something mentioned in an earlier quotation if the two quotations are closely related in time and context. This allows a quotation to be broken up by narrative material without interfering with the pro-sumti within it. Here's an example:
la djan. cusku lu mi klama le zarci li'u .i la .alis. cusku lu mi go'i li'u
John says [quote] I go-to the store [unquote]. Alice says [quote] I [repeat] [unquote].
John says, “I am going to the store.” Alice says, “Me too.”

Of course, there is no problem with narrative material referring to something within a quotation: people who quote, unlike people who are quoted, are aware of what they are doing.

Indefinite pro-sumti and pro-bridi: the zo'e-series and the co'e-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning zo'e KOhA zo'e-series the obvious value zu'i KOhA zo'e-series the typical value zi'o KOhA zo'e-series the nonexistent value

co'e GOhA co'e-series has the obvious relationship </tab>

The cmavo of the zo'e-series represent indefinite, unspecified sumti. The cmavo zo'e represents an elliptical value for this sumti place; it is the optional spoken place holder when a sumti is skipped without being specified. Note that the elliptical value is not always the typical value. The properties of ellipsis lead to an elliptical sumti being defined as “whatever I want it to mean but haven't bothered to figure out, or figure out how to express”.

The cmavo zu'i, on the other hand, represents the typical value for this place of this bridi:

mi klama le bartu be le zdani le nenri be le zdani zu'i zu'i
I go to-the outside of the house from-the inside of the house [by-typical-route] [by-typical-means]

In Example , the first zu'i probably means something like “by the door”, and the second zu'i probably means something like “on foot”, those being the typical route and means for leaving a house. On the other hand, if you are at the top of a high rise during a fire, neither zu'i is appropriate. It's also common to use zu'i in “by standard” places.

Finally, the cmavo zi'o represents a value which does not even exist. When a bridi fills one of its places with zi'o, what is really meant is that the selbri has a place which is irrelevant to the true relationship the speaker wishes to express. For example, the place structure of zbasu is:

actor x1 makes x2 from materials x3

Consider the sentence

Living things are made from cells.

This cannot be correctly expressed as:

loi jmive cu se zbasu [zo'e] fi loi selci
The-mass-of living-things is-made [by-something] from the-mass-of cells

because the zo'e, expressed or understood, in Example indicates that there is still a “maker” in this relationship. We do not generally suppose, however, that someone “makes” living things from cells. The best answer is probably to find a different selbri, one which does not imply a “maker”: however, an alternative strategy is to use zi'o to eliminate the maker place:

loi jmive cu se zbasu zi'o loi selci
The-mass-of living-things is-made [without-maker] from the-mass-of cells.

Note: The use of zi'o to block up, as it were, one place of a selbri actually creates a new selbri with a different place structure. Consider the following examples:

mi zbasu le dinju loi mudri
I make the building from-some-of-the-mass-of wood.
I make the building out of wood.
zi'o zbasu le dinju loi mudri
[without-maker] makes the building from-some-of-the-mass-of wood.
The building is made out of wood.
mi zbasu zi'o loi mudri
I make [without-thing-made] from-some-of-the-mass-of wood.
I build using wood.
mi zbasu le dinju zi'o
I make the building [without-material].
I make the building.

If Example is true, then Example through Example must be true also. However, Example does not correspond to any sentence with three regular (non-zi'o) sumti.

The pro-bridi co'e (which by itself constitutes the co'e-series of selma'o GOhA) represents the elliptical selbri. Lojban grammar does not allow the speaker to merely omit a selbri from a bridi, although any or all sumti may be freely omitted. Being vague about a relationship requires the use of co'e as a selbri place-holder:

mi troci le nu mi co'e le vorme
I try the event-of my [doing-the-obvious-action] to-the door.
I try the door.

The English version means, and the Lojban version probably means, that I try to open the door, but the relationship of opening is not actually specified; the Lojbanic listener must guess it from context. Lojban, unlike English, makes it clear that there is an implicit action that is not being expressed.

The form of co'e was chosen to resemble zo'e; the cmavo do'e of selma'o BAI (see Section 13.5) also belongs to the same group of cmavo.

Note that do'i, of the di'u-series, is also a kind of indefinite pro-sumti: it is indefinite in referent, but is restricted to referring only to an utterance.

Reflexive and reciprocal pro-sumti: the vo'a-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning vo'a KOhA vo'a-series x1 of this bridi vo'e KOhA vo'a-series x2 of this bridi vo'i KOhA vo'a-series x3 of this bridi vo'o KOhA vo'a-series x4 of this bridi vo'u KOhA vo'a-series x5 of this bridi

soi SOI reciprocity

se'u SEhU soi terminator </tab>

The cmavo of the vo'a-series are pro-sumti anaphora, like those of the ri-series, but have a specific function. These cmavo refer to the other places of the same bridi; the five of them represent up to five places. The same vo'a-series cmavo mean different things in different bridi. Some examples:

mi lumci vo'a
I wash myself
mi klama le zarci vo'e
I go to the store from itself [by some route unspecified].

To refer to places of neighboring bridi, constructions like

le se go'i ku do the job: this refers to the 2nd place of the previous main bridi, as explained in Section 10.5.

The cmavo of the vo'a-series are also used with soi (of selma'o SOI) to precisely express reciprocity, which in English is imprecisely expressed with a discursive phrase like “vice versa”:

mi prami do soi vo'a vo'e
I love you [reciprocity] [x1 of this bridi] [x2 of this bridi].
I love you and vice versa (swapping “I” and “you”).

The significance of

soi vo'a vo'e is that the bridi is still true even if the x1 (specified by vo'a) and the x2 (specified by vo'e) places are interchanged. If only a single sumti follows soi, then the sumti immediately preceding soi is understood to be one of those involved:
mi prami do soi vo'a
I love you [reciprocity] [x1 of this bridi].

again involves the x1 and x2 places.

Of course, other places can be involved, and other sumti may be used in place of vo'a-series cmavo, provided those other sumti can be reasonably understood as referring to the same things mentioned in the bridi proper. Here are several examples that mean the same thing:

mi bajykla ti ta soi vo'e
mi bajykla ti ta soi vo'e vo'i
soi vo'e vo'i mi bajykla ti ta
I runningly-go to this from that and vice versa (to that from this).

The elidable terminator for soi is se'u (selma'o SEhU), which is normally needed only if there is just one sumti after the soi, and the soi construction is not at the end of the bridi. Constructions using soi are free modifiers, and as such can go almost anywhere. Here is an example where se'u is required:

mi bajykla ti soi vo'i se'u ta
I runningly-go to-this [reciprocity] [x3 of this bridi] from-that
I run to this from that and vice versa.

sumti and bridi questions: ma and mo

The following cmavo are discussed in this section:


Lojban questions are more fully explained in Section 18.48, but ma and mo are listed in this chapter for completeness. The cmavo ma asks for a sumti to make the bridi true:

do klama ma
You go to-what-destination?
Where are you going?

The cmavo mo, on the other hand, asks for a selbri which makes the question bridi true. If the answer is a full bridi, then the arguments of the answer override the arguments in the question, in the same manner as the go'i-series cmavo. A simple example is:

do mo
What predicate is true as applied to you?
How are you?
What are you doing?
What are you?

Example is a truly pregnant question that will have several meanings depending on context.

(One thing it probably does not mean is “Who are you?” in the sense “What is your name/identity?”, which is better expressed by:

ma cmene do
What sumti is-the-name-of you?
What is your name?

or even

doi ma
O [what sumti?]

which uses the vocative doi to address someone, and simultaneously asks who the someone is.)

A further example of mo:

lo mo prenu cu darxi do .i barda
A [what selbri?] type-of person hit you? (Observative:) A big thing.
Which person hit you? The big one.

When ma or mo is repeated, multiple questions are being asked simultaneously:

ma djuno ma
[What sumti] knows [what sumti]?
Who knows what?

Relativized pro-sumti: ke'a

The following cmavo are discussed in this section:


This pro-sumti is used in relative clauses (explained in Chapter 12) to indicate how the sumti being relativized fits within the clause. For example:

mi catlu lo mlatu poi [zo'e] zbasu ke'a lei slasi
I see a cat such-that something-unspecified makes the-thing-being-relativized [the cat] from-some-mass-of plastic.
I see a cat made of plastic.

If ke'a were omitted from Example , it might be confused with:

mi catlu lo mlatu poi [ke'a] zbasu lei slasi
I see a cat such-that the-thing-being-relativized [the cat] makes a-mass-of plastic
I see a cat that makes plastic.

The anaphora cmavo ri cannot be used in place of ke'a in Example and Example , because the relativized sumti is not yet complete when the ke'a appears.

Note that ke'a is used only with relative clauses, and not with other embedded bridi such as abstract descriptions. In the case of relative clauses within relative clauses, ke'a may be subscripted to make the difference clear (See Section 12.9).

Abstraction focus pro-sumti: ce'u

The following cmavo are discussed in this section:


The cmavo ce'u is used within abstraction bridi, particularly property abstractions introduced by the cmavo ka. Abstractions, including the uses of ce'u, are discussed in full in Chapter 16.

In brief: Every property abstraction specifies a property of one of the sumti in it; that sumti place is filled by using ce'u. This convention enables us to distinguish clearly between:

le ka ce'u gleki
the property-of (X being-happy)
the property of being happy


le ka gleki ce'u
the property-of (being-happy about-X)
the property of being that which someone is happy about

Bound variable pro-sumti and pro-bridi: the da-series and the bu'a-series

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning da KOhA da-series something-1 de KOhA da-series something-2 di KOhA da-series something-3

bu'a GOhA bu'a-series some-predicate-1 bu'e GOhA bu'a-series some-predicate-2 bu'i GOhA bu'a-series some-predicate-3 </tab>

Bound variables belong to the predicate-logic part of Lojban, and are listed here for completeness only. Their semantics is explained in Chapter 17. It is worth mentioning that the Lojban translation of Example is:

la djan. cu lafti da poi grana ku'o gi'e desygau da
John raised something-1 which is-a-stick and shake-did something-1.
John picked up a stick and shook it.

Pro-sumti and pro-bridi cancelling

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning da'o DAhO cancel all pro-sumti/pro-bridi </tab>

How long does a pro-sumti or pro-bridi remain stable? In other words, once we know the referent of a pro-sumti or pro-bridi, how long can we be sure that future uses of the same cmavo have the same referent? The answer to this question depends on which series the cmavo belongs to.

Personal pro-sumti are stable until there is a change of speaker or listener, possibly signaled by a vocative. Assignable pro-sumti and pro-bridi last indefinitely or until rebound with goi or cei. Bound variable pro-sumti and pro-bridi also generally last until re-bound; details are available in Section 17.13.

Utterance pro-sumti are stable only within the utterance in which they appear; similarly, reflexive pro-sumti are stable only within the bridi in which they appear; and ke'a is stable only within its relative clause. Anaphoric pro-sumti and pro-bridi are stable only within narrow limits depending on the rules for the particular cmavo.

Demonstrative pro-sumti, indefinite pro-sumti and pro-bridi, and sumti and bridi questions potentially change referents every time they are used.

However, there are ways to cancel all pro-sumti and pro-bridi, so that none of them have known referents. (Some, such as mi, will acquire the same referent as soon as they are used again after the cancellation.) The simplest way to cancel everything is with the cmavo da'o of selma'o DAhO, which is used solely for this purpose; it may appear anywhere, and has no effect on the grammar of texts containing it. One use of da'o is when entering a conversation, to indicate that one's pro-sumti assignments have nothing to do with any assignments already made by other participants in the conversation.

In addition, the cmavo ni'o and no'i of selma'o NIhO, which are used primarily to indicate shifts in topic, may also have the effect of canceling pro-sumti and pro-bridi assignments, or of reinstating ones formerly in effect. More explanations of NIhO can be found in Section 18.46.

The identity predicate: du

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning du GOhA identity </tab>

The cmavo du has the place structure:

x1 is identical with x2, x3, ...

and appears in selma'o GOhA for reasons of convenience: it is not a pro-bridi. du serves as mathematical “=”, and outside mathematical contexts is used for defining or identifying. Mathematical examples may be found in Chapter ELG-ERROR in Template:Lch.

The main difference between

ko'a du le nanmu
It-1 is-identical-to the man


ko'a mintu le nanmu
It-1 is-the-same-as the man

is this defining nature. Example presumes that the speaker is responding to a request for information about what ko'a refers to, or that the speaker in some way feels the need to define ko'a for later reference. A bridi with du is an identity sentence, somewhat metalinguistically saying that all attached sumti are representations for the same referent. There may be any number of sumti associated with du, and all are said to be identical.Example , however, predicates; it is used to make a claim about the identity of ko'a, which presumably has been defined previously.

Note: du historically is derived from dunli, but dunli has a third place which du lacks: the standard of equality.

lujvo based on pro-sumti

There exist rafsi allocated to a few cmavo of selma'o KOhA, but they are rarely used. (See Section 10.15 for a complete list.) The obvious way to use them is as internal sumti, filling in an appropriate place of the gismu or lujvo to which they are attached; as such, they usually stand as the first rafsi in their lujvo.

Thus donta'a, meaning “you-talk”, would be interpreted as

tavla be do, and would have the place structure
t1 talks to you about subject t3 in language t4

since t2 (the addressee) is already known to be do.

On the other hand, the lujvo donma'o, literally “you-cmavo”, which means “a second person personal pronoun”, would be interpreted as

cmavo be zo do, and have the place structure:
c1 is a second person pronoun in language c4

since both the c2 place (the grammatical class) and the c3 place (the meaning) are obvious from the context do.

An anticipated use of rafsi for cmavo in the fo'a series is to express lujvo which can't be expressed in a convenient rafsi form, because they are too long to express, or are formally inconvenient (fu'ivla, cmene, and so forth.) An example would be:

fo'a goi le kulnrsu,omi .i lo fo'arselsanga
x6 stands for Finnish-culture. An x6-song.

Finally, lujvo involving zi'o are also possible, and are fully discussed in Chapter ELG-ERROR in Template:Lch. In brief, the convention is to use the rafsi for zi'o as a prefix immediately followed by the rafsi for the number of the place to be deleted. Thus, if we consider a beverage (something drunk without considering who, if anyone, drinks it) as a

se pinxe be zi'o, the lujvo corresponding to this is zilrelselpinxe (deleting the second place of
se pinxe). Deleting the x1 place in this fashion would move all remaining places up by one. This would mean that zilpavypinxe has the same place structure as zilrelselpinxe, and
lo zilpavypinxe, like
lo zilrelselpinxe, refers to a beverage, and not to a non-existent drinker.

The pro-bridi co'e, du, and bu'a also have rafsi, which can be used just as if they were gismu. The resulting lujvo have (except for

du- based lujvo) highly context-dependent meanings.

KOhA cmavo by series

<tab class=wikitable> cmavo selma'o subclass meaning mi-series: mi I (rafsi: mib) do you (rafsi: don and “doi”) mi'o you and I mi'a I and others, we but not you ma'a you and I and others do'o you and others ko you-imperative

ti-series: ti this here; something nearby (rafsi: tif) ta that there; something distant (rafsi: taz) tu that yonder; something far distant (rafsi: tuf)

di'u-series: di'u the previous utterance de'u an earlier utterance da'u a much earlier utterance di'e the next utterance de'e a later utterance da'e a much later utterance dei this very utterance do'i some utterance

ko'a-series: ko'a it-1; 1st assignable pro-sumti ko'e it-2; 2nd assignable pro-sumti ko'i it-3; 3rd assignable pro-sumti ko'o it-4; 4th assignable pro-sumti ko'u it-5; 5th assignable pro-sumti

fo'a it-6; 6th assignable pro-sumti (rafsi: fo'a) fo'e it-7; 7th assignable pro-sumti (rafsi: fo'e) fo'i it-8; 8th assignable pro-sumti (rafsi: fo'i) fo'o it-9; 9th assignable pro-sumti fo'u it-10; 10th assignable pro-sumti

ri-series: ri (repeats the last sumti) ra (repeats a previous sumti) ru (repeats a long-ago sumti)

zo'e-series: zo'e the obvious value zu'i the typical value zi'o the nonexistent value (rafsi: zil)

vo'a-series: vo'a x1 of this bridi vo'e x2 of this bridi vo'i x3 of this bridi vo'o x4 of this bridi vo'u x5 of this bridi

da-series: da something-1 (rafsi: dav/dza) de something-2 di something-3

others: ke'a relativized sumti ma sumti question ce'u abstraction focus </tab>

GOhA and other pro-bridi by series

<tab class=wikitable> cmavo selma'o subclass meaning broda-series (not GOhA): broda is-1; 1st assignable pro-bridi brode is-2; 2nd assignable pro-bridi brodi is-3; 3rd assignable pro-bridi brodo is-4; 4th assignable pro-bridi brodu is-5; 5th assignable pro-bridi

go'i-series: go'i (repeats the last bridi) go'a (repeats a previous bridi) go'u (repeats a long-ago bridi) go'e (repeats the last-but-one bridi) go'o (repeats a future bridi) nei (repeats the current bridi) no'a (repeats the next outer bridi)

bu'a-series: bu'a some-predicate-1 (rafsi: bul) bu'e some-predicate-2 bu'i some-predicate-3

others: co'e has the obvious relationship (rafsi: com/ co'e) mo bridi question du identity: x1 is identical to x2, x3 ... (rafsi: dub/du'o) </tab>

Other cmavo discussed in this chapter

<tab class=wikitable> cmavo selma'o subclass meaning goi GOI pro-sumti assignment (ko'a-series) cei CEI pro-bridi assignment (broda-series) ra'o RAhO pro-sumti/pro-bridi update soi SOI reciprocity se'u SEhU soi terminator da'o DAhO cancel all pro-sumti/pro-bridi </tab>

Relative Clauses

What are you pointing at?

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning poi NOI restrictive relative clause introducer ke'a GOhA relative pro-sumti ku'o KUhO relative clause terminator </tab>

Let us think about the problem of communicating what it is that we are pointing at when we are pointing at something. In Lojban, we can refer to what we are pointing at by using the pro-sumti ti if it is nearby, or ta if it is somewhat further away, or tu if it is distant. (Pro-sumti are explained in full in Chapter 10.)

However, even with the assistance of a pointing finger, or pointing lips, or whatever may be appropriate in the local culture, it is often hard for a listener to tell just what is being pointed at. Suppose one is pointing at a person (in particular, in the direction of his or her face), and says:

Example 12.1:

ti cu barda
This-one is-big.

What is the referent of ti? Is it the person? Or perhaps it is the person's nose? Or even (for ti can be plural as well as singular, and mean “these ones” as well as “this one”) the pores on the person's nose?

To help solve this problem, Lojban uses a construction called a “relative clause”. Relative clauses are usually attached to the end of sumti, but there are other places where they can go as well, as explained later in this chapter. A relative clause begins with a word of selma'o NOI, and ends with the elidable terminator ku'o (of selma'o KUhO). As you might suppose, noi is a cmavo of selma'o NOI; however, first we will discuss the cmavo poi, which also belongs to selma'o NOI.

In between the poi and the ku'o appears a full bridi, with the same syntax as any other bridi. Anywhere within the bridi of a relative clause, the pro-sumti ke'a (of selma'o KOhA) may be used, and it stands for the sumti to which the relative clause is attached (called the “relativized sumti”). Here are some examples before we go any further:

Example 12.2:

ti poi ke'a prenu ku'o cu barda
This-thing such-that-(IT is-a-person) is-large.
This thing which is a person is big.
This person is big.
Example 12.3:


ti poi ke'a nazbi ku'o cu barda
This-thing such-that-(IT is-a-nose) is-large.
This thing which is a nose is big.
This nose is big.
Example 12.4:

ti poi ke'a nazbi kapkevna ku'o cu barda
This-thing such-that-(IT is-a-nose-type-of skin-hole) is-big.
These things which are nose-pores are big.
These nose-pores are big.

In the literal translations throughout this chapter, the word “IT”, capitalized, is used to represent the cmavo ke'a. In each case, it serves to represent the sumti (in Example 12.2 through Example 12.4, the cmavo ti) to which the relative clause is attached.

Of course, there is no reason why ke'a needs to appear in the x1 place of a relative clause bridi; it can appear in any place, or indeed even in a sub-bridi within the relative clause bridi. Here are two more examples:

Example 12.5:

tu poi le mlatu pu lacpu ke'a ku'o cu ratcu
That-distant-thing such-that (the cat [past] drags IT) is-a-rat.
That thing which the cat dragged is a rat.
What the cat dragged is a rat.
Example 12.6:

ta poi mi djica le nu mi ponse ke'a [kei] ku'o cu bloti
That-thing such-that( I desire the event-of( I own IT ) ) is-a-boat.
That thing that I want to own is a boat.

In Example 12.6, ke'a appears in an abstraction clause (abstractions are explained in Chapter 16) within a relative clause.

Like any sumti, ke'a can be omitted. The usual presumption in that case is that it then falls into the x1 place:

Example 12.7:

ti poi nazbi cu barda
This-thing which is-a-nose is-big.

almost certainly means the same thing as Example 12.3. However, ke'a can be omitted if it is clear to the listener that it belongs in some place other than x1:

Example 12.8:

tu poi le mlatu pu lacpu cu ratcu
That-distant-thing which the cat [past] drags is-a-rat

is equivalent to Example 12.4.

As stated before, ku'o is an elidable terminator, and in fact it is almost always elidable. Throughout the rest of this chapter, ku'o will not be written in any of the examples unless it is absolutely required: thus, Example 12.2 can be written:

Example 12.9:

ti poi prenu cu barda
That which is-a-person is-big.
That person is big.

without any change in meaning. Note that poi is translated “which” rather than “such-that” when ke'a has been omitted from the x1 place of the relative clause bridi. The word “which” is used in English to introduce English relative clauses: other words that can be used are “who” and “that”, as in:

Example 12.10:

I saw a man who was going to the store.


Example 12.11:

The building that the school was located in is large.

In Example 12.10 the relative clause is “who was going to the store”, and in Example 12.11 it is “that the school was located in”. Sometimes “who”, “which”, and “that” are used in literal translations in this chapter in order to make them read more smoothly.

Incidental relative clauses

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning noi NOI incidental relative clause introducer </tab>

There are two basic kinds of relative clauses: restrictive relative clauses introduced by poi, and incidental (sometimes called simply “non-restrictive”) relative clauses introduced by noi. The difference between restrictive and incidental relative clauses is that restrictive clauses provide information that is essential to identifying the referent of the sumti to which they are attached, whereas incidental relative clauses provide additional information which is helpful to the listener but is not essential for identifying the referent of the sumti. All of the examples in Section are restrictive relative clauses: the information in the relative clause is essential to identification. (The title of this chapter, though, uses an incidental relative clause.)

Consider the following examples:

Example 12.12:

le gerku poi blanu cu barda
The dog which is-blue is-large.
The dog which is blue is large.
Example 12.13:

le gerku noi blanu cu barda
The dog incidentally-which is-blue is-large.
The dog, which is blue, is large.

In Example 12.12, the information conveyed by

poi blanu is essential to identifying the dog in question: it restricts the possible referents from dogs in general to dogs that are blue. This is why poi relative clauses are called restrictive. In Example 12.13, on the other hand, the dog which is referred to has presumably already been identified clearly, and the relative clause
noi blanu just provides additional information about it. (If in fact the dog hasn't been identified clearly, then the relative clause does not help identify it further.)

In English, the distinction between restrictive and incidental relative clauses is expressed in writing by surrounding incidental, but not restrictive, clauses with commas. These commas are functioning as parentheses, because incidental relative clauses are essentially parenthetical. This distinction in punctuation is represented in speech by a difference in tone of voice. In addition, English restrictive relative clauses can be introduced by “that” as well as “which” and “who”, whereas incidental relative clauses cannot begin with “that”. Lojban, however, always uses the cmavo poi and noi rather than punctuation or intonation to make the distinction.

Here are more examples of incidental relative clauses:

Example 12.14:

mi noi jdice cu zvati
I who-incidentally am-a-judge am-at [some-place].
I, a judge, am present.

In this example, mi is already sufficiently restricted, and the additional information that I am a judge is being provided solely for the listener's edification.

Example 12.15:

xu do viska le mi karce noi blabi
[True?] You see my car incidentally-which is-white.
Do you see my car, which is white?

In Example 12.15, the speaker is presumed to have only one car, and is providing incidental information that it is white. (Alternatively, he or she might have more than one car, since

le karce can be plural, in which case the incidental information is that each of them is white.) Contrast Example 12.16 with a restrictive relative clause:
Example 12.16:

xu do viska le mi karce poi blabi
[True?] You see my car which is-white.
Do you see my car that is white?
Do you see my white car?

Here the speaker probably has several cars, and is restricting the referent of the sumti

le mi karce (and thereby the listener's attention) to the white one only. Example 12.16 means much the same as Example 12.17, which does not use a relative clause:
Example 12.17:

xu do viska le mi blabi karce
[True?] You see my white car.
Do you see my car, the white one?

So a restrictive relative clause attached to a description can often mean the same as a description involving a tanru. However,

blabi karce, like all tanru, is somewhat vague: in principle, it might refer to a car which carries white things, or even express some more complicated concept involving whiteness and car-ness; the restrictive relative clause of Example 12.16 can only refer to a car which is white, not to any more complex or extended concept.

Relative phrases

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning pe GOI restrictive association po GOI restrictive possession po'e GOI restrictive intrinsic possession po'u GOI restrictive identification ne GOI incidental association no'u GOI incidental identification

ge'u GEhU relative phrase terminator </tab>

There are types of relative clauses (those which have a certain selbri) which are frequently wanted in Lojban, and can be expressed using a shortcut called a relative phrase. Relative phrases are introduced by cmavo of selma'o GOI, and consist of a GOI cmavo followed by a single sumti.

Here is an example of pe, plus an equivalent sentence using a relative clause:

Example 12.18:

le stizu pe mi cu blanu
The chair associated-with me is-blue.
My chair is blue.
Example 12.19:

le stizu poi ke'a srana mi cu blanu
The chair such-that( IT is-associated-with me) is-blue.

In Example 12.18 and Example 12.19, the link between the chair and the speaker is of the loosest kind.

Here is an example of po:

Example 12.20:

le stizu po mi cu xunre
The chair specific-to me is red.
Example 12.21:

le stizu poi ke'a se steci srana mi cu xunre
The chair such-that (IT is-specifically associated-with me) is-red.

Example 12.20 and Example 12.21 contrast with Example 12.18 and Example 12.19: the chair is more permanently connected with the speaker. A plausible (though not the only possible) contrast between Example 12.18 and Example 12.20 is that

pe mi would be appropriate for a chair the speaker is currently sitting on (whether or not the speaker owned that chair), and
po mi for a chair owned by the speaker (whether or not he or she was currently occupying it).

As a result, the relationship expressed between two sumti by po is usually called “possession”, although it does not necessarily imply ownership, legal or otherwise. The central concept is that of specificity ( steci in Lojban).

Here is an example of po'e, as well as another example of po:

Example 12.22:

le birka po'e mi cu spofu
The arm intrinsically-possessed-by me is-broken
Example 12.23:

le birka poi jinzi ke se steci srana mi cu spofu
The arm which is-intrinsically (specifically associated-with) me is-broken.
Example 12.24:

le botpi po mi cu spofu
The bottle specific-to me is-broken

Example 12.22 and Example 12.23 on the one hand, and Example 12.24 on the other, illustrate the contrast between two types of possession called “intrinsic” and “extrinsic”, or sometimes “inalienable” and “alienable”, respectively. Something is intrinsically (or inalienably) possessed by someone if the possession is part of the possessor, and cannot be changed without changing the possessor. In the case of Example 12.22, people are usually taken to intrinsically possess their arms: even if an arm is cut off, it remains the arm of that person. (If the arm is transplanted to another person, however, it becomes intrinsically possessed by the new user, though, so intrinsic possession is a matter of degree.)

By contrast, the bottle of Example 12.24 can be given away, or thrown away, or lost, or stolen, so it is possessed extrinsically (alienably). The exact line between intrinsic and extrinsic possession is culturally dependent. The U.S. Declaration of Independence speaks of the “inalienable rights” of men, but just what those rights are, and even whether the concept makes sense at all, varies from culture to culture.

Note that Example 12.22 can also be expressed without a relative clause:

Example 12.25:

le birka be mi cu spofu
The arm of-body me is broken

reflecting the fact that the gismu birka has an x2 place representing the body to which the arm belongs. Many, but not all, cases of intrinsic possession can be thus covered without using po'e by placing the possessor into the appropriate place of the description selbri.

Here is an example of po'u:

Example 12.26:

le gerku po'u le mi pendo cu cinba mi
The dog which-is my friend kisses me.
Example 12.27:

le gerku poi du le mi pendo cu cinba mi
The dog which = my friend kisses me.

The cmavo po'u does not represent possession at all, but rather identity. (Note that it means

poi du and its form was chosen to suggest the relationship.)

In Example 12.26, the use of po'u tells us that

le gerku and
le mi pendo represent the same thing. Consider the contrast between Example 12.26 and:
Example 12.28:

le mi pendo po'u le gerku cu cinba mi
My friend which-is the dog kisses me.

The facts of the case are the same, but the listener's knowledge about the situation may not be. In Example 12.26, the listener is presumed not to understand which dog is meant by

le gerku, so the speaker adds a relative phrase clarifying that it is the particular dog which is the speaker's friend.Example 12.28, however, assumes that the listener does not know which of the speaker's friends is referred to, and specifies that it is the friend that is the dog (which dog is taken to be obvious). Here is another example of the same contrast:
Example 12.29:

le tcadu po'u la nu,iork
The city of New York [not another city]
Example 12.30:

la nu,iork po'u le tcadu
New York the city (not the state or some other New York)

The principle that the possessor and the possessed may change places applies to all the GOI cmavo, and allows for the possibility of odd effects:

Example 12.31:

le kabri pe le mi pendo cu cmalu
The cup associated-with my friend is small.
My friend's cup is small
Example 12.32:

le mi pendo pe le kabri cu cmalu
My friend associated-with the cup is small.
My friend, the one with the cup, is small.

Example 12.31 is useful in a context which is about my friend, and states that his or her cup is small, whereas Example 12.32 is useful in a context that is primarily about a certain cup, and makes a claim about “my friend of the cup”, as opposed to some other friend of mine. Here the cup appears to “possess” the person! English can't even express this relationship with a possessive – “the cup's friend of mine” looks like nonsense – but Lojban has no trouble doing so.

Finally, the cmavo ne and no'u stand to pe and po'u, respectively, as noi does to

poi- they provide incidental information:
Example 12.33:

le blabi gerku ne mi cu batci do
The white dog, incidentally-associated-with me, bites you.
The white dog, which is mine, bites you.

In Example 12.33, the white dog is already fully identified (after all, presumably the listener knows which dog bit him or her!). The fact that it is yours is merely incidental to the main bridi claim.

Distinguishing between po'u and no'u can be a little tricky. Consider a room with several men in it, one of whom is named Jim. If you don't know their names, I might say:

Example 12.34:

le nanmu no'u la djim. cu terpemci
The man, incidentally-who-is Jim, is-a-poet.
The man, Jim, is a poet.

Here I am saying that one of the men is a poet, and incidentally telling you that he is Jim. But if you do know the names, then

Example 12.35:

le nanmu po'u la djim. cu terpemci
The man who-is Jim is-a-poet.
The man Jim is a poet.

is appropriate. Now I am using the fact that the man I am speaking of is Jim in order to pick out which man I mean.

It is worth mentioning that English sometimes over-specifies possession from the Lojban point of view (and the point of view of many other languages, including ones closely related to English). The idiomatic English sentence

Example 12.36:

The man put his hands in his pockets.

seems strange to a French- or German-speaking person: whose pockets would he put his hands into? and even odder, whose hands would he put into his pockets? In Lojban, the sentence

Example 12.37:

le nanmu cu punji le xance le daski
The man puts the hand at-locus-the pocket.

is very natural. Of course, if the man is in fact putting his hands into another's pockets, or another's hands into his pockets, the fact can be specified.

Finally, the elidable terminator for GOI cmavo is ge'u of selma'o GEhU; it is almost never required. However, if a logical connective immediately follows a sumti modified by a relative phrase, then an explicit ge'u is needed to allow the connective to affect the relativized sumti rather than the sumti of the relative phrase. (What about the cmavo after which selma'o GOI is named? It is discussed in Section 10.4, as it is not semantically akin to the other kinds of relative phrases, although the syntax is the same.)

Multiple relative clauses: zi'e

<tab class=wikitable> cmavo selma'o subclass meaning zi'e ZIhE relative clause joiner </tab>

Sometimes it is necessary or useful to attach more than one relative clause to a sumti. This is made possible in Lojban by the cmavo zi'e (of selma'o ZIhE), which is used to join one or more relative clauses together into a single unit, thus making them apply to the same sumti. For example:

Example 12.38:

le gerku poi blabi zi'e poi batci le nanmu cu klama
The dog which is white and which bites the man goes.

The most usual translation of zi'e in English is “and”, but zi'e is not really a logical connective: unlike most of the true logical connectives (which are explained in Chapter ELG-ERROR in Template:Lch), it cannot be converted into a logical connection between sentences.

It is perfectly correct to use zi'e to connect relative clauses of different kinds:

Example 12.39:

le gerku poi blabi zi'e noi le mi pendo cu ponse ke'a cu klama
The dog that-is (white) and incidentally-such-that (my friend owns IT) goes.
The dog that is white, which my friend owns, is going.

In Example 12.39, the restrictive clause

poi blabi specifies which dog is referred to, but the incidental clause
noi le mi pendo cu ponse is mere incidental information: the listener is supposed to already have identified the dog from the
poi blabi. Of course, the meaning (though not necessarily the emphasis) is the same if the incidental clause appears first.

It is also possible to connect relative phrases with zi'e, or a relative phrase with a relative clause:

Example 12.40:

le botpi po mi zi'e poi blanu cu spofu
The bottle specific-to me and which-is blue is-broken.
My blue bottle is broken.

Note that if the colloquial translation of Example 12.40 were “My bottle, which is blue, is broken”, then noi rather than poi would have been correct in the Lojban version, since that version of the English implies that you do not need to know the bottle is blue. As written, Example 12.40 suggests that I probably have more than one bottle, and the one in question needs to be picked out as the blue one.

Example 12.41:

mi ba zutse le stizu pe mi zi'e po do zi'e poi xunre
I [future] sit-in the chair associated-with me and specific-to you and which-is red.
I will sit in my chair (really yours), the red one.

Example 12.41 illustrates that more than two relative phrases or clauses can be connected with zi'e. It almost defies colloquial translation because of the very un-English contrast between

pe mi, implying that the chair is temporarily connected with me, and
po do, implying that the chair has a more permanent association with you. (Perhaps I am a guest in your house, in which case the chair would naturally be your property.)

Here is another example, mixing a relative phrase and two relative clauses, a restrictive one and a non-restrictive one:

Example 12.42:

mi ba citka le dembi pe mi zi'e poi cpana le mi palta zi'e noi do dunda ke'a mi
I [future] eat the beans associated-with me and which are-upon my plate and which-incidentally you gave IT to-me.
I'll eat my beans that are on my plate, the ones you gave me.

Non-veridical relative clauses: voi

<tab class=wikitable> cmavo selma'o subclass meaning voi NOI non-veridical relative clause introducer </tab>

There is another member of selma'o NOI which serves to introduce a third kind of relative clause: voi. Relative clauses introduced by voi are restrictive, like those introduced by poi. However, there is a fundamental difference between poi and voi relative clauses. A poi relative clause is said to be veridical, in the same sense that a description using lo or loi is: it is essential to the interpretation that the bridi actually be true. For example:

Example 12.43:

le gerku poi blabi cu klama
The dog which is-white goes.

it must actually be true that the dog is white, or the sentence constitutes a miscommunication. If there is a white dog and a brown dog, and the speaker uses

le gerku poi blabi to refer to the brown dog, then the listener will not understand correctly. However,
Example 12.44:

le gerku voi blabi cu klama
The dog which-I-describe-as white goes.

puts the listener on notice that the dog in question may not actually meet objective standards (whatever they are) for being white: only the speaker can say exactly what is meant by the term. In this way, voi is like le; the speaker's intention determines the meaning.

As a result, the following two sentences

Example 12.45:

le nanmu cu ninmu
That-which-I-describe-as a-man is-a-woman.
The “guy” is actually a gal.
Example 12.46:

ti voi nanmu cu ninmu
This-thing which-I-describe-as a-man is-a-woman.

mean essentially the same thing (except that Example 12.46 involves pointing thanks to the use of ti, whereas Example 12.45 doesn't), and neither one is self-contradictory: it is perfectly all right to describe something as a man (although perhaps confusing to the listener) even if it actually is a woman.

Relative clauses and descriptors

So far, this chapter has described the various kinds of relative clauses (including relative phrases). The list is now complete, and the rest of the chapter will be concerned with the syntax of sumti that include relative clauses. So far, all relative clauses have appeared directly after the sumti to which they are attached. This is the most common position (and originally the only one), but a variety of other placements are also possible which produce a variety of semantic effects.

There are actually three places where a relative clause can be attached to a description sumti: after the descriptor ( le, lo, or whatever), after the embedded selbri but before the elidable terminator (which is ku), and after the ku. The relative clauses attached to descriptors that we have seen have occupied the second position. Thus Example 12.43, if written out with all elidable terminators, would appear as:

Example 12.47:

le gerku poi blabi ku'o ku cu klama vau
The (dog which (is-white) ) goes.
The dog which is white is going.

Here ku'o is the terminator paired with poi and ku with le, and vau is the terminator of the whole bridi.

When a simple descriptor using le, like

le gerku, has a relative clause attached, it is purely a matter of style and emphasis where the relative clause should go. Therefore, the following examples are all equivalent in meaning to Example 12.47:
Example 12.48:

le poi blabi ku'o gerku cu klama
The such-that (it-is-white) dog goes.
Example 12.49:

le gerku ku poi blabi cu klama
The (dog) which is-white goes.Example 12.47 will seem most natural to speakers of languages like English, which always puts relative clauses after the noun phrases they are attached to; Example 12.48, on the other hand, may seem more natural to Finnish or Chinese speakers, who put the relative clause first. Note that in Example 12.48, the elidable terminator ku'o must appear, or the selbri of the relative clause ( blabi) will merge with the selbri of the description ( gerku), resulting in an ungrammatical sentence. The purpose of the form appearing in Example 12.49 will be apparent shortly.

As is explained in detail in Section 8.6, two different numbers (known as the “inner quantifier” and the “outer quantifier”) can be attached to a description. The inner quantifier specifies how many things the descriptor refers to: it appears between the descriptor and the description selbri. The outer quantifier appears before the descriptor, and specifies how many of the things referred to by the descriptor are involved in this particular bridi. In the following example,

Example 12.50:

re le mu prenu cu klama le zarci
Two-of the five persons go to-the market.
Two of the five people [that I have in mind] are going to the market.

mu is the inner quantifier and re is the outer quantifier. Now what is meant by attaching a relative clause to the sumti

re le mu prenu? Suppose the relative clause is
poi ninmu (meaning “who are women”). Now the three possible attachment points discussed previously take on significance.
Example 12.51:

re le poi ninmu ku'o mu prenu cu klama le zarci
Two of the such-that([they] are-women) five persons go to-the market.
Two women out of the five persons go to the market.
Example 12.52:

re le mu prenu poi ninmu [ku] cu klama le zarci
Two of the (five persons which are-women) go to-the market.
Two of the five women go to the market.
Example 12.53:

re le mu prenu ku poi ninmu cu klama le zarci
(Two of the five persons) which are-women go to-the market.
Two women out of the five persons go to the market.

As the parentheses show, Example 12.52 means that all five of the persons are women, whereas Example 12.53 means that the two who are going to the market are women. How do we remember which is which? If the relative clause comes after the explicit ku, as in Example 12.53, then the sumti as a whole is qualified by the relative clause. If there is no ku, or if the relative clause comes before an explicit ku, then the relative clause is understood to apply to everything which the underlying selbri applies to.

What about Example 12.51? By convention, it means the same as Example 12.53, and it requires no ku, but it does typically require a ku'o instead. Note that the relative clause comes before the inner quantifier.

When le is the descriptor being used, and the sumti has no explicit outer quantifier, then the outer quantifier is understood to be ro (meaning “all”), as is explained in Section 8.6. Thus

le gerku is taken to mean “all of the things I refer to as dogs”, possibly all one of them. In that case, there is no difference between a relative clause after the ku or before it. However, if the descriptor is lo, the difference is quite important:
Example 12.54:

lo prenu ku noi blabi cu klama le zarci
(Some persons) incidentally-which are-white go to-the market.
Some people, who are white, go to the market.
Example 12.55:

lo prenu noi blabi [ku] cu klama le zarci
Some (persons incidentally-which are-white) go to-the market.
Some of the people, who by the way are white, go to the market.

Both Example 12.54 and Example 12.55 tell us that one or more persons are going to the market. However, they make very different incidental claims. Now, what does

lo prenu noi blabi mean? Well, the default inner quantifier is ro (meaning “all”), and the default outer quantifier is su'o (meaning “at least one”). Therefore, we must first take all persons, then choose at least one of them. That one or more people will be going.

In Example 12.54, the relative clause described the sumti once the outer quantifier was applied: one or more people, who are white, are going. But in Example 12.55, the relative clause actually describes the sumti before the outer quantification is applied, so that it ends up meaning “First take all persons – by the way, they're all white”. But not all people are white, so the incidental claim being made here is false.

The safe strategy, therefore, is to always use ku when attaching a noi relative clause to a lo descriptor. Otherwise we may end up claiming far too much.

When the descriptor is la, indicating that what follows is a selbri used for naming, then the positioning of relative clauses has a different significance. A relative clause inside the ku, whether before or after the selbri, is reckoned part of the name; a relative clause outside the ku is not. Therefore,

Example 12.56:

mi viska la nanmu poi terpa le ke'a xirma [ku]

I see that-named ( “man which fears the of-IT horse”).

I see Man Afraid Of His Horse.

says that the speaker sees a person with a particular name, who does not necessarily fear any horses, whereas

Example 12.57:

mi viska la nanmu ku poi terpa le ke'a xirma.

I see that-named( “Man”) which fears the of-IT horse.

I see the person named “Man” who is afraid of his horse.

refers to one (or more) of those named “Man”, namely the one(s) who are afraid of their horses.

Finally, so-called indefinite sumti like

re karce, which means almost the same as
re lo karce (which in turn means the same as
re lo ro karce), can have relative clauses attached; these are taken to be of the outside-the- ku variety. Here is an example:
Example 12.58:

mi ponse re karce [ku] poi xekri
I possess two cars which-are black.

The restrictive relative clause only affects the two cars being affected by the main bridi, not all cars that exist. It is ungrammatical to try to place a relative clause within an indefinite sumti (that is, before an explicitly expressed terminating ku.) Use an explicit lo instead.

Possessive sumti

In Example 12.15 through Example 12.17, the sumti

le mi karce appears, glossed as “my car”. Although it might not seem so, this sumti actually contains a relative phrase. When a sumti appears between a descriptor and its description selbri, it is actually a pe relative phrase. So
Example 12.59:

le mi karce cu xunre
My car is-red.


Example 12.60:

le pe mi karce cu xunre
The (associated-with me) car is-red.

mean exactly the same thing. Furthermore, since there are no special considerations of quantifiers here,

Example 12.61:

le karce pe mi cu xunre
The car associated-with me is-red.

means the same thing as well. A sumti like the one in Example 12.59 is called a “possessive sumti”. Of course, it does not really indicate possession in the sense of ownership, but like pe relative phrases, indicates only weak association; you can say

le mi karce even if you've only borrowed it for the night. (In English, “my car” usually means
le karce po mi, but we do not have the same sense of possession in “my seat on the bus”; Lojban simply makes the weaker sense the standard one.) The inner sumti,

mi in Example 12.59, is correspondingly called the “possessor sumti”.

Historically, possessive sumti existed before any other kind of relative phrase or clause, and were retained when the machinery of relative phrases and clauses as detailed in this chapter so far was slowly built up. When preposed relative clauses of the Example 12.60 type were devised, possessive sumti were most easily viewed as a special case of them.

Although any sumti, however complex, can appear in a full-fledged relative phrase, only simple sumti can appear as possessor sumti, without a pe. Roughly speaking, the legal possessor sumti are: pro-sumti, quotations, names and descriptions, and numbers. In addition, the possessor sumti may not be preceded by a quantifier, as such a form would be interpreted as the unusual “descriptor + quantifier + sumti” type of description. All these sumti forms are explained in full in Chapter 8.

Here is an example of a description used in a possessive sumti:

Example 12.62:

le le nanmu ku karce cu blanu
The (associated-with-the man) car is blue.
The man's car is blue.

Note the explicit ku at the end of the possessor sumti, which prevents the selbri of the possessor sumti from merging with the selbri of the main description sumti. Because of the need for this ku, the most common kind of possessor sumti are pro-sumti, especially personal pro-sumti, which require no elidable terminator. Descriptions are more likely to be attached with relative phrases.

And here is a number used as a possessor sumti:

Example 12.63:

le li mu jdice se bende
The of-the-number-five judging team-member
Juror number 5

which is not quite the same as “the fifth juror”; it simply indicates a weak association between the particular juror and the number 5.

A possessive sumti may also have regular relative clauses attached to it. This would need no comment if it were not for the following special rule: a relative clause immediately following the possessor sumti is understood to affect the possessor sumti, not the possessive. For example:

Example 12.64:

le mi noi sipna vau karce cu na klama
The of-me incidentally-which-(is-sleeping) car isn't going.

means that my car isn't going; the incidental claim of

noi sipna applies to me, not my car, however. If I wanted to say that the car is sleeping (whatever that might mean) I would need:
Example 12.65:

le mi karce poi sipna cu na klama
The of-me car which sleeps isn't going.

Note that Example 12.64 uses vau rather than ku'o at the end of the relative clause: this terminator ends every simple bridi and is almost always elidable; in this case, though, it is a syllable shorter than the equally valid alternative, ku'o.

Relative clauses and complex sumti: vu'o

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning vu'o VUhO relative clause attacher </tab>

Normally, relative clauses attach only to simple sumti or parts of sumti: pro-sumti, names and descriptions, pure numbers, and quotations. An example of a relative clause attached to a pure number is:

Example 12.66:

li pai noi na'e frinu namcu
The-number pi, incidentally-which is-a-non- fraction number
The irrational number pi

And here is an incidental relative clause attached to a quotation:

Example 12.67:

lu mi klama le zarci li'u noi mi cusku ke'a cu jufra
[quote] I go to-the market [unquote] incidentally-which-(I express IT) is-a-sentence.
“I'm going to the market”, which I'd said, is a sentence.

which may serve to identify the author of the quotation or some other relevant, but subsidiary, fact about it. All such relative clauses appear only after the simple sumti, never before it.

In addition, sumti with attached sumti qualifiers of selma'o LAhE or NAhE+BO (which are explained in detail in Section 8.9) can have a relative clause appearing after the qualifier and before the qualified sumti, as in:

Example 12.68:

la'e poi tolcitno vau lu le xunre cmaxirma li'u cu zvati le vu kumfa
A-referent-of (which is-old) [quote] The Red Small-horse [unquote] is-at the [far distance] room.
An old “The Red Pony” is in the far room.

Example 12.68 is a bit complex, and may need some picking apart. The quotation

lu le xunre cmaxirma li'u means the string of words “The Red Pony”. If the

la'e at the beginning of the sentence were omitted, Example 12.68 would claim that a certain string of words is in a room distant from the speaker. But obviously a string of words can't be in a room! The effect of the la'e is to modify the sumti so that it refers not to the words themselves, but to the referent of those words, a novel by John Steinbeck (presumably in Lojban translation). The particular copy of “The Red Pony” is identified by the restrictive relative clause. Example 12.68 means exactly the same as:

Example 12.69:

la'e lu le xunre cmaxirma li'u lu'u poi to'ercitno cu zvati le vu kumfa
A-referent-of ([quote] The Red Small-horse [unquote]) which is-old is-at the [far distance] room.

and the two sentences can be considered stylistic variants. Note the required lu'u terminator, which prevents the relative clause from attaching to the quotation itself: we do not wish to refer to an old quotation!

Sometimes, however, it is important to make a relative clause apply to the whole of a more complex sumti, one which involves logical or non-logical connection (explained in Chapter ELG-ERROR in Template:Lch). For example,

Example 12.70:

la frank. .e la djordj. noi nanmu cu klama le zdani
Frank and George incidentally-who is-a-man go to-the house.
Frank and George, who is a man, go to the house.

The incidental claim in Example 12.70 is not that Frank and George are men, but only that George is a man, because the incidental relative clause attaches only to

la djordj, the immediately preceding simple sumti.

To make a relative clause attach to both parts of the logically connected sumti in Example 12.70, a new cmavo is needed, vu'o (of selma'o VUhO). It is placed between the sumti and the relative clause, and extends the sphere of influence of that relative clause to the entire preceding sumti, including however many logical or non-logical connectives there may be.

Example 12.71:

la frank. .e la djordj. vu'o noi nanmu cu klama le zdani
Frank and George incidentally-who are-men go to-the house.
Frank and George, who are men, go to the house.

The presence of vu'o here means that the relative clause

noi nanmu extends to the entire logically connected sumti
la frank. .e la djordj.; in other words, both Frank and George are claimed to be men, as the colloquial translation shows.

English is able to resolve the distinction correctly in the case of Example 12.70 and Example 12.71 by making use of number: “who is” rather than “who are”. Lojban doesn't distinguish between singular and plural verbs: nanmu can mean “is a man” or “are men”, so another means is required. Furthermore, Lojban's mechanism works correctly in general: if nanmu (meaning “is-a-man”) were replaced with

pu bajra ( “ran”), English would have to make the distinction some other way:
Example 12.72:

la frank. .e la djordj. noi pu bajra cu klama le zdani
Frank and (George who [past] runs) go to-the house.
Frank and George, who ran, go to the house.
Example 12.73:

la frank. .e la djordj. vu'o noi pu bajra cu klama le zdani
(Frank and George) who [past] run go to-the house.
Frank and George, who ran, go to the house.

In spoken English, tone of voice would serve; in written English, one or both sentences would need rewriting.

Relative clauses in vocative phrases

Vocative phrases are explained in more detail in Section 8.10. Briefly, they are a method of indicating who a sentence or discourse is addressed to: of identifying the intended listener. They take three general forms, all beginning with cmavo from selma'o COI or DOI (called “vocative words”; there can be one or many), followed by either a name, a selbri, or a sumti. Here are three examples:

Example 12.74:

coi. frank.
Hello, Frank.
Example 12.75:

co'o xirma
Goodbye, horse.
Example 12.76:

fi'i la frank. .e la djordj.
Welcome, Frank and George!

Note that Example 12.75 says farewell to something which doesn't really have to be a horse, something that the speaker simply thinks of as being a horse, or even might be something (a person, for example) who is named “Horse”. In a sense, Example 12.75 is ambiguous between

co'o le xirma and
co'o la xirma, a relatively safe semantic ambiguity, since names are ambiguous in general: saying “George” doesn't distinguish between the possible Georges.

Similarly, Example 12.74 can be thought of as an abbreviation of:

Example 12.77:

coi la frank.
Hello, the-one-named “Frank”.

Syntactically, vocative phrases are a kind of free modifier, and can appear in many places in Lojban text, generally at the beginning or end of some complete construct; or, as in Example 12.74 to Example 12.76, as sentences by themselves.

As can be seen, the form of vocative phrases is similar to that of sumti, and as you might expect, vocative phrases allow relative clauses in various places. In vocative phrases which are simple names (after the vocative words), any relative clauses must come just after the names:

Example 12.78:

coi. frank. poi xunre se bende
Hello, Frank who is-a-red team-member
Hello, Frank from the Red Team!

The restrictive relative clause in Example 12.78 suggests that there is some other Frank (perhaps on the Green Team) from whom this Frank, the one the speaker is greeting, must be distinguished.

A vocative phrase containing a selbri can have relative clauses either before or after the selbri; both forms have the same meaning. Here are some examples:

Example 12.79:

co'o poi mi zvati ke'a ku'o xirma
Goodbye, such-that-(I am-at IT) horse
Goodbye, horse where I am!
Example 12.80:

co'o xirma poi mi zvati
Goodbye, horse such-that-(I am-at-it).Example 12.79 and Example 12.80 mean the same thing. In fact, relative clauses can appear in both places.

Relative clauses within relative clauses

For the most part, these are straightforward and uncomplicated: a sumti that is part of a relative clause bridi may itself be modified by a relative clause:

Example 12.81:

le prenu poi zvati le kumfa poi blanu cu masno
The person who is-in the room which is-blue is-slow.

However, an ambiguity can exist if ke'a is used in a relative clause within a relative clause: does it refer to the outermost sumti, or to the sumti within the outer relative clause to which the inner relative clause is attached? The latter. To refer to the former, use a subscript on ke'a:

Example 12.82:

le prenu poi zvati le kumfa poi ke'axire zbasu ke'a cu masno
The person who is-in the room which IT-sub-2 built IT is-slow.
The person who is in the room which he built is slow.

Here, the meaning of “IT-sub-2” is that sumti attached to the second relative clause, counting from the innermost, is used. Therefore,

ke'axipa (IT-sub-1) means the same as plain


Alternatively, you can use a prenex (explained in full in Chapter 17), which is syntactically a series of sumti followed by the special cmavo zo'u, prefixed to the relative clause bridi:

Example 12.83:

le prenu poi ke'a goi ko'a zo'u ko'a zvati le kumfa poi ke'a goi ko'e zo'u ko'a zbasu ke'a cu masno
The man who (IT = it1 : it1 is-in the room which (IT = it2 : it1 built it2) is-slow.Example 12.83 is more verbose than Example 12.82, but may be clearer, since it explicitly spells out the two ke'a cmavo, each on its own level, and assigns them to the assignable cmavo ko'a and ko'e (explained in Section 10.4).

Index of relative clause cmavo

Relative clause introducers (selma'o NOI): <tab class=wikitable> cmavo selma'o subclass meaning Relative clause introducers (selma'o NOI):

noi incidental clauses poi restrictive clauses voi restrictive clauses (non-veridical) Relative phrase introducers (selma'o GOI):

goi pro-sumti assignment pe restrictive association ne incidental association po extrinsic (alienable) possession po'e intrinsic (inalienable) possession po'u restrictive identification no'u incidental identification Relativizing pro-sumti (selma'o KOhA):

ke'a pro-sumti for relativized sumti Relative clause joiner (selma'o ZIhE):

zi'e joins relative clauses applying to a single sumti Relative clause associator (selma'o VUhO):

vu'o causes relative clauses to apply to all of a complex sumti Elidable terminators (each its own selma'o):

ku'o relative clause elidable terminator ge'u relative phrase elidable terminator </tab>

Bridi relative clause

...pu'o se ciska

  1. A broda B C. In order to inject A brode G J use A poi ke'a brode G J cu broda B C
  2. A broda B C .i fabo brode G J. We can rephrase that as A broda B C soi G J brode.
  3. A broda B C .i febo A brode. We can rephrase that as A poi brode lo nei cu broda B C.

converts the following bridi into nonce modal/sumti tag clause; the nesting bridi is automatically replicated in the first abstraction place of the clause

The first unfilled place of the clause containing abstraction (needs to be present in the selbri of the subordinate clause) is automatically applied to the whole nesting bridi if not explicitly defined otherwise with ke'a. See also fi'o

lo ractu cu citka lo cirla sepi'o lo denci be vo'a = (emulating guaspi) lo ractu cu citka lo cirla soi se tutci be lo denci be vo'a [se'u]
operating level: sumti bridi
non-restrictive: noi soi
restrictive: poi ??? GIhEKs?
to ... toi is outside this grammar.

To Boston Via The Road Go I, With An Excursion Into The Land Of Modals


The basic type of Lojban sentence is the bridi: a claim by the speaker that certain objects are related in a certain way. The objects are expressed by Lojban grammatical forms called sumti; the relationship is expressed by the Lojban grammatical form called a selbri.

The sumti are not randomly associated with the selbri, but according to a systematic pattern known as the “place structure” of the selbri. This chapter describes the various ways in which the place structure of Lojban bridi is expressed and by which it can be manipulated. The place structure of a selbri is a sequence of empty slots into which the sumti associated with that selbri are placed. The sumti are said to occupy the places of the selbri.

For our present purposes, every selbri is assumed to have a well-known place structure. If the selbri is a brivla, the place structure can be looked up in a dictionary (or, if the brivla is a lujvo not in any dictionary, inferred from the principles of lujvo construction as explained in Chapter ELG-ERROR in Template:Lch); if the selbri is a tanru, the place structure is the same as that of the final component in the tanru.

The stock example of a place structure is that of the gismu

x1 comes/goes to destination x2 from origin x3 via route x4 employing means of transport x5.

The “x1 ... x5” indicates that klama is a five-place predicate, and show the natural order (as assigned by the language engineers) of those places: agent, destination, origin, route, means.

The place structures of brivla are not absolutely stable aspects of the language. The work done so far has attempted to establish a basic place structure on which all users can, at first, agree. In the light of actual experience with the individual selbri of the language, there will inevitably be some degree of change to the brivla place structures.

Standard bridi form: cu

The following cmavo is discussed in this section:

cmavo selma'o subclass meaning
cu CU prefixed selbri separator

The most usual way of constructing a bridi from a selbri such as klama and an appropriate number of sumti is to place the sumti intended for the x1 place before the selbri, and all the other sumti in order after the selbri, thus:

Example 1
mi cu klama la bastn. la .atlantas. le dargu le karce
I go to-Boston from-Atlanta via-the road using-the car.

Here the sumti are assigned to the places as follows:

x1 agent mi
x2 destination la bastn.
x3 origin la .atlantas.
x4 route le dargu
x5 means le karce

(Note: Many of the examples in the rest of this chapter will turn out to have the same meaning as Example 1; this fact will not be reiterated.)

This ordering, with the x1 place before the selbri and all other places in natural order after the selbri, is called “standard bridi form”, and is found in the bulk of Lojban bridi, whether used in main sentences or in subordinate clauses. However, many other forms are possible, such as:

Example 2
mi la bastn. la .atlantas. le dargu le karce cu klama
I, to-Boston from-Atlanta via-the road using-the car, go.

Here the selbri is at the end; all the sumti are placed before it. However, the same order is maintained.

Similarly, we may split up the sumti, putting some before the selbri and others after it:

Example 3
mi la bastn. cu klama la .atlantas. le dargu le karce
I to-Boston go from-Atlanta via-the road using-the car.

All of the variant forms in this section and following sections can be used to place emphasis on the part or parts which have been moved out of their standard places. Thus, Example 2 places emphasis on the selbri (because it is at the end); Example 3 emphasizes :la bastn., because it has been moved before the selbri. Moving more than one component may dilute this emphasis. It is permitted, but no stylistic significance has yet been established for drastic reordering.

In all these examples, the cmavo cu (belonging to selma'o CU) is used to separate the selbri from any preceding sumti. It is never absolutely necessary to use cu. However, providing it helps the reader or listener to locate the selbri quickly, and may make it possible to place a complex sumti just before the selbri, allowing the speaker to omit elidable terminators, possibly a whole stream of them, that would otherwise be necessary.

The general rule, then, is that the selbri may occur anywhere in the bridi as long as the sumti maintain their order. The only exception (and it is an important one) is that if the selbri appears first, the x1 sumti is taken to have been omitted:

Example 4
klama la bastn. la .atlantas. le dargu le karce
A-goer to-Boston from-Atlanta via-the road using-the car.
Goes to-Boston from-Atlanta via-the road using-the car.
Look: a goer to Boston from Atlanta via the road using the car!

Here the x1 place is empty: the listener must guess from context who is going to Boston. In Example 4, klama is glossed “a goer” rather than “go” because “Go” at the beginning of an English sentence would suggest a command: “Go to Boston!”. Example is not a command, simply a normal statement with the x1 place unspecified, causing the emphasis to fall on the selbri klama. Such a bridi, with empty x1, is called an “observative”, because it usually calls on the listener to observe something in the environment which would belong in the x1 place. The third translation above shows this observative nature. Sometimes it is the relationship itself which the listener is asked to observe.

(There is a way to both provide a sumti for the x1 place and put the selbri first in the bridi: See Example .)

Suppose the speaker desires to omit a place other than the x1 place? (Presumably it is obvious or, for one reason or another, not worth saying.) Places at the end may simply be dropped:

Example 5
mi klama la bastn. la .atlantas.
I go to-Boston from-Atlanta (via an unspecified route, using an unspecified means).

Example 5 has empty x4 and x5 places: the speaker does not specify the route or the means of transport. However, simple omission will not work for a place when the places around it are to be specified: in

Example 6
mi klama la bastn. la .atlantas. le karce
I go to-Boston from-Atlanta via-the car.
le karce occupies the x4 place, and therefore Example 6 means:
I go to Boston from Atlanta, using the car as a route.

This is nonsense, since a car cannot be a route. What the speaker presumably meant is expressed by:

Example 7
mi klama la bastn. la .atlantas. zo'e le karce
I go to-Boston from-Atlanta via-something-unspecified using-the car.

Here the sumti cmavo zo'e is used to explicitly fill the x4 place; zo'e means “the unspecified thing” and has the same meaning as leaving the place empty: the listener must infer the correct meaning from context.

Tagging places: FA

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
fa FA tags x1 place
fe FA tags x2 place
fi FA tags x3 place
fo FA tags x4 place
fu FA tags x5 place
fi'a FA place structure question

In sentences like Example , it is easy to get lost and forget which sumti falls in which place, especially if the sumti are more complicated than simple names or descriptions. The place structure tags of selma'o FA may be used to help clarify place structures. The five cmavo fa, fe, fi, fo, and fu may be inserted just before the sumti in the x1 to x5 places respectively:

Example 8
fa mi cu klama fe la bastn. fi la .atlantas. fo le dargu fu le karce
x1= I go x2= Boston x3= Atlanta x4= the road x5= the car.
I go to Boston from Atlanta via the road using the car.

In Example , the tag fu before :le karce clarifies that :le karce occupies the x5 place of klama. The use of fu tells us nothing about the purpose or meaning of the x5 place; it simply says that :le karce occupies it.

In Example 8, the tags are overkill; they serve only to make Example 7 even longer than it is. Here is a better illustration of the use of FA tags for clarification:

Example 9
fa mi klama fe le zdani be mi be'o poi nurma vau fi la nu,IORK.
x1= I go x2= (the house of me) which is-rural x3= New York.

In Example 9, the place structure of klama is as follows:

x1 agent mi
x2 destination le zdani be mi be'o poi nurma vau
x3 origin la nu,IORK.
x4 route (empty)
x5 means (empty)

The fi tag serves to remind the hearer that what follows is in the x3 place of klama; after listening to the complex sumti occupying the x2 place, it's easy to get lost.

Of course, once the sumti have been tagged, the order in which they are specified no longer carries the burden of distinguishing the places. Therefore, it is perfectly all right to scramble them into any order desired, and to move the selbri to anywhere in the bridi, even the beginning:

Example 10
klama fa mi fi la .atlantas. fu le karce fe la bastn. fo le dargu
go x1= I x3= Atlanta x5= the car x2= Boston x4= the road.
Go I from Atlanta using the car to Boston via the road.

Note that no cu is permitted before the selbri in Example 10, because cu separates the selbri from any preceding sumti, and Example 10 has no such sumti.

Example 11
fu le karce fo le dargu fi la .atlantas. fe la bastn. cu klama fa mi
x5= the car x4= the road x3= Atlanta x2= Boston go x1=I
Using the car, via the road, from Atlanta to Boston go I.

Example 11 exhibits the reverse of the standard bridi form seen in Example 1 and Example 2, but still means exactly the same thing. If the FA tags were left out, however, producing:

Example 12
le karce le dargu la .atlantas. la bastn. cu klama mi
The car to-the road from-Atlanta via-Boston goes using-me.
The car goes to the road from Atlanta, with Boston as the route, using me as a means of transport.

the meaning would be wholly changed, and in fact nonsensical.

Tagging places with FA cmavo makes it easy not only to reorder the places but also to omit undesirable ones, without any need for zo'e or special rules about the x1 place:

Example 13
klama fi la .atlantas. fe la bastn. fu le karce
A-goer x3= Atlanta x2= Boston x5 = the car.
A goer from Atlanta to Boston using the car.

Here the x1 and x4 places are empty, and so no sumti are tagged with fa or fo; in addition, the x2 and x3 places appear in reverse order.

What if some sumti have FA tags and others do not? The rule is that after a FA-tagged sumti, any sumti following it occupy the places numerically succeeding it, subject to the proviso that an already-filled place is skipped:

Example 14
klama fa mi la bastn. la .atlantas. le dargu le karce
Go x1= I x2= Boston x3= Atlanta x4= the road x5= the car.
Go I to Boston from Atlanta via the road using the car.

In Example 14, the fa causes mi to occupy the x1 place, and then the following untagged sumti occupy in order the x2 through x5 places. This is the mechanism by which Lojban allows placing the selbri first while specifying a sumti for the x1 place.

Here is a more complex (and more confusing) example:

Example 15
mi klama fi la .atlantas. le dargu fe la bastn. le karce
I go x3= Atlanta, the road x2= Boston, the car.
I go from Atlanta via the road to Boston using the car.

In Example 15, mi occupies the x1 place because it is the first sumti in the sentence (and is before the selbri). The second sumti, :la .atlantas., occupies the x3 place by virtue of the tag fi, and :le dargu occupies the x4 place as a result of following :la .atlantas.. Finally, :la bastn. occupies the x2 place because of its tag fe, and :le karce skips over the already-occupied x3 and x4 places to land in the x5 place.

Such a convoluted use of tags should probably be avoided except when trying for a literal translation of some English (or other natural-language) sentence; the rules stated here are merely given so that some standard interpretation is possible.

It is grammatically permitted to tag more than one sumti with the same FA cmavo. The effect is that of making more than one claim:

Example 16
[fa] la rik. fa la djein. klama [fe] le skina fe le zdani fe le zarci
[x1=] Rick x1= Jane goes-to [x2=] the movie x2= the house x2= the office

may be taken to say that both Rick and Jane go to the movie, the house, and the office, merging six claims into one. More likely, however, it will simply confuse the listener. There are better ways, involving logical connectives (explained in Chapter ELG-ERROR in Template:Lch), to say such things in Lojban. In fact, putting more than one sumti into a place is odd enough that it can only be done by explicit FA usage: this is the motivation for the proviso above, that already-occupied places are skipped. In this way, no sumti can be forced into a place already occupied unless it has an explicit FA cmavo tagging it.

The cmavo fi'a also belongs to selma'o FA, and allows Lojban users to ask questions about place structures. A bridi containing fi'a is a question, asking the listener to supply the appropriate other member of FA which will make the bridi a true statement:

Example 17
fi'a do dunda [fe] le vi rozgu
[what place]? you give x2= the nearby rose
In what way are you involved in the giving of this rose?
Are you the giver or the receiver of this rose?

In Example 17, the speaker uses the selbri dunda, whose place structure is: dunda :x1 gives x2 to x3

The tagged sumti :fi'a do indicates that the speaker wishes to know whether the sumti do falls in the x1 or the x3 place (the x2 place is already occupied by :le rozgu). The listener can reply with a sentence consisting solely of a FA cmavo: fa if the listener is the giver, fi if he/she is the receiver.

I have inserted the tag fe in brackets into Example 17, but it is actually not necessary, because fi'a does not count as a numeric tag; therefore, :le vi rozgu would necessarily be in the x2 place even if no tag were present, because it immediately follows the selbri.

There is also another member of FA, namely fai, which is discussed in Section 13.11.

Conversion: SE

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
se SE 2nd place conversion
te SE 3rd place conversion
ve SE 4th place conversion
xe SE 5th place conversion

So far we have seen ways to move sumti around within a bridi, but the actual place structure of the selbri has always remained untouched. The conversion cmavo of selma'o SE are incorporated within the selbri itself, and produce a new selbri (called a converted selbri) with a different place structure. In particular, after the application of any SE cmavo, the number and purposes of the places remain the same, but two of them have been exchanged, the x1 place and another. Which place has been exchanged with x1 depends on the cmavo chosen. Thus, for example, when se is used, the x1 place is swapped with the x2 place.

Note that the cmavo of SE begin with consecutive consonants in alphabetical order. There is no “1st place conversion” cmavo, because exchanging the x1 place with itself is a pointless maneuver.

Here are the place structures of

se klama:
x1 is the destination of x2's going from x3 via x4 using x5


te klama:
x1 is the origin and x2 the destination of x3 going via x4 using x5


ve klama:
x1 is the route to x2 from x3 used by x4 going via x5


xe klama:
x1 is the means in going to x2 from x3 via x4 employed by x5

Note that the place structure numbers in each case continue to be listed in the usual order, x1 to x5.

Consider the following pair of examples:

Example 18
la bastn. cu se klama mi
Boston is-the-destination of-me.
Boston is my destination.
Boston is gone to by me.

Example 19
fe la bastn. cu klama fa mi
x2 = Boston go x1=I.
To Boston go I.

Example 18 and Example 19 mean the same thing, in the sense that there is a relationship of going with the speaker as the agent and Boston as the destination (and with unspecified origin, route, and means). Structurally, however, they are quite different. Example has :la bastn. in the x1 place and mi in the x2 place of the selbri

se klama, and uses standard bridi order; Example has mi in the x1 place and :la bastn. in the x2 place of the selbri klama, and uses a non-standard order.

The most important use of conversion is in the construction of descriptions. A description is a sumti which begins with a cmavo of selma'o LA or LE, called the descriptor, and contains (in the simplest case) a selbri. We have already seen the descriptions :le dargu and :le karce. To this we could add:

Example 20
le klama
the go-er, the one who goes

In every case, the description is about something which fits into the x1 place of the selbri. In order to get a description of a destination (that is, something fitting the x2 place of klama), we must convert the selbri to :se klama, whose x1 place is a destination. The result is

Example 21
le se klama
the destination gone to by someone

Likewise, we can create three more converted descriptions:

Example 22
le te klama
the origin of someone's going

Example 23
le ve klama
the route of someone's going

Example 24
le xe klama
the means by which someone goes

Example 23 does not mean “the route” plain and simple: that is :le pluta, using a different selbri. It means a route that is used by someone for an act of klama; that is, a journey with origin and destination. A “road” on Mars, on which no one has traveled or is ever likely to, may be called :le pluta, but it cannot be

le ve klama, since there exists no one for whom it is :le ve klama be fo da (the route taken in an actual journey by someone [da]).

When converting selbri that are more complex than a single brivla, it is important to realize that the scope of a SE cmavo is only the following brivla (or equivalent unit). In order to convert an entire tanru, it is necessary to enclose the tanru in keke'e brackets:

Example 25
mi se ke blanu zdani [ke'e] ti
I [2nd conversion] blue house this-thing

The place structure of :blanu zdani (blue house) is the same as that of zdani, by the rule given in Section . The place structure of zdani is:

zdani :x1 is a house/nest/lair/den for inhabitant x2

The place structure of

se ke blanu zdani [ke'e] is therefore:
x1 is the inhabitant of the blue house (etc.) x2

Consequently, Example means:

I am the inhabitant of the blue house which is this thing.

Conversion applied to only part of a tanru has subtler effects which are explained in Section 6.10.

It is grammatical to convert a selbri more than once with SE; later (inner) conversions are applied before earlier (outer) ones. For example, the place structure of

se te klama is achieved by exchanging the x1 and x2 place of
te klama, producing:

x1 is the destination and x2 is the origin of x3 going via x4 using x5

On the other hand,

te se klama has a place structure derived from swapping the x1 and x3 places of
se klama:
x1 is the origin of x2's going to x3 via x4 using x5

which is quite different. However, multiple conversions like this are never necessary. Arbitrary scrambling of places can be achieved more easily and far more intelligibly with FA tags, and only a single conversion is ever needed in a description.

(Although no one has made any real use of it, it is perhaps worth noting that compound conversions of the form

setese, where the first and third cmavo are the same, effectively swap the two given places while leaving the others, including x1, alone:
setese (or equivalently
tesete) swap the x2 and x3 places, whereas
texete (or
xetexe) swap the x3 and x5 places.)

Modal places: FIhO, FEhU

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
fi'o FIhO modal place prefix
fe'u FEhU modal terminator

Sometimes the place structures engineered into Lojban are inadequate to meet the needs of actual speech. Consider the gismu viska, whose place structure is: viska :x1 sees x2 under conditions x3

Seeing is a threefold relationship, involving an agent (le viska), an object of sight (le se viska), and an environment that makes seeing possible (le te viska). Seeing is done with one or more eyes, of course; in general, the eyes belong to the entity in the x1 place.

Suppose, however, that you are blind in one eye and are talking to someone who doesn't know that. You might want to say, “I see you with the left eye.” There is no place in the place structure of viska such as “with eye x4” or the like. Lojban allows you to solve the problem by adding a new place, changing the relationship:

Example 26
mi viska do fi'o kanla [fe'u] le zunle
I see you [modal] eye: the left-thing
I see you with the left eye.

The three-place relation viska has now acquired a fourth place specifying the eye used for seeing. The combination of the cmavo fi'o (of selma'o FIhO) followed by a selbri, in this case the gismu kanla, forms a tag which is prefixed to the sumti filling the new place, namely

le zunle. The semantics of
fi'o kanla le zunle is that
le zunle fills the x1 place of kanla, whose place structure is

kanla :x1 is an/the eye of body x2


le zunle is an eye. The x2 place of kanla is unspecified and must be inferred from the context. It is important to remember that even though
le zunle is placed following
fi'o kanla, semantically it belongs in the x1 place of kanla. The selbri may be terminated with fe'u (of selma'o FEhU), an elidable terminator which is rarely required unless a non-logical connective follows the tag (omitting fe'u in that case would make the connective affect the selbri).

The term for such an added place is a “modal place”, as distinguished from the regular numbered places. (This use of the word “modal” is specific to the Loglan Project, and does not agree with the standard uses in either logic or linguistics, but is now too entrenched to change easily.) The fi'o construction marking a modal place is called a “modal tag”, and the sumti which follows it a “modal sumti”; the purely Lojban terms

sumti tcita and
seltcita sumti, respectively, are also commonly used. Modal sumti may be placed anywhere within the bridi, in any order; they have no effect whatever on the rules for assigning unmarked bridi to numbered places, and they may not be marked with FA cmavo.

Consider Example again. Another way to view the situation is to consider the speaker's left eye as a tool, a tool for seeing. The relevant selbri then becomes pilno, whose place structure is pilno :x1 uses x2 as a tool for purpose x3

and we can rewrite Example 26 as

Example 27
mi viska do fi'o se pilno le zunle kanla
I see you [modal] [conversion] use: the left eye.
I see you using my left eye.

Here the selbri belonging to the modal is

se pilno. The conversion of pilno is necessary in order to get the “tool” place into x1, since only x1 can be the modal sumti. The “tool user” place is the x2 of
se pilno (because it is the x1 of pilno) and remains unspecified. The tag
fi'o pilno would mean “with tool user”, leaving the tool unspecified.

Modal tags: BAI

There are certain selbri which seem particularly useful in constructing modal tags. In particular, pilno is one of them. The place structure of pilno is: pilno :x1 uses x2 as a tool for purpose x3

and almost any selbri which represents an action may need to specify a tool. Having to say

fi'o se pilno frequently would make many Lojban sentences unnecessarily verbose and clunky, so an abbreviation is provided in the language design: the compound cmavo sepi'o.

Here se is used before a cmavo, namely pi'o, rather than before a brivla. The meaning of this cmavo, which belongs to selma'o BAI, is exactly the same as that of

fi'o pilno fe'u. Since what we want is a tag based on
se pilno rather than
pilno- the tool, not the tool user – the grammar allows a BAI cmavo to be converted using a SE cmavo. Example may therefore be rewritten as:

Example 28
mi viska do sepi'o le zunle kanla
I see you with-tool: the left eye
I see you using my left eye.

The compound cmavo sepi'o is much shorter than

fi'o se pilno [fe'u] and can be thought of as a single word meaning “with-tool”. The modal tag pi'o, with no

se, similarly means “with-tool-user”, probably a less useful concept. Nevertheless, the parallelism with the place structure of pilno makes the additional syllable worthwhile.

Some BAI cmavo make sense with as well as without a SE cmavo; for example, ka'a, the BAI corresponding to the gismu klama, has five usable forms corresponding to the five places of klama respectively:


Any of these tags may be used to provide modal places for bridi, as in the following examples:

Example 29
la .eivn. cu vecnu loi flira cinta ka'a mi
Avon sells a-mass-of face paint with-goer me.
I am a traveling cosmetics salesperson for Avon.

Example 29 may seem a bit strained, but it illustrates the way in which an existing selbri, vecnu in this case, may have a place added to it which might otherwise seem utterly unrelated.)

Example 30
mi cadzu seka'a la bratfyd.
I walk with-destination Bradford.
I am walking to Bradford.

Example 31
bloti teka'a la nu,IORK.
[Observative:] is-a-boat with-origin New York
A boat from New York!

Example 32
do bajra veka'a lo djine
You run with-route a circle.
You are running in circles.

Example 33
mi citka xeka'a le vinji
I eat with-means-of-transport the airplane.
I eat in the airplane.

There are sixty-odd cmavo of selma'o BAI, based on selected gismu that seemed useful in a variety of settings. The list is somewhat biased toward English, because many of the cmavo were selected on the basis of corresponding English prepositions and preposition compounds such as “with”, “without”, and “by means of”. The BAI cmavo, however, are far more precise than English prepositions, because their meanings are fixed by the place structures of the corresponding gismu.

All BAI cmavo have the form CV'V or CVV. Most of them are CV'V, where the C is the first consonant of the corresponding gismu and the two Vs are the two vowels of the gismu. The table in Section 13.15 shows the exceptions.

There is one additional BAI cmavo that is not derived from a gismu: do'e. This cmavo is used when an extra place is needed, but it seems useful to be vague about the semantic implications of the extra place:

Example 34
lo nanmu be do'e le berti cu klama le tcadu
Some man [related to] the north came to-the city.
A man of the north came to the city.

Here :le berti is provided as a modal place of the selbri nanmu, but its exact significance is vague, and is paralleled in the colloquial translation by the vague English preposition “of”. Example also illustrates a modal place bound into a selbri with be. This construction is useful when the selbri of a description requires a modal place; this and other uses of be are more fully explained in Section 6.6.

Modal sentence connection: the causals

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
ri'a BAI rinka modal: physical cause
ki'u BAI krinu modal: justification
mu'i BAI mukti modal: motivation
ni'i BAI nibli modal: logical entailment

This section has two purposes. On the one hand, it explains the grammatical construct called “modal sentence connection”. On the other, it exemplifies some of the more useful BAI cmavo: the causals. (There are other BAI cmavo which have causal implications: ja'e means “with result”, and so seja'e means “with cause of unspecified nature”; likewise, gau means “with agent” and tezu'e means “with purpose”. These other modal cmavo will not be further discussed here, as my purpose is to explain modal sentence connection rather than Lojbanic views of causation.)

There are four causal gismu in Lojban, distinguishing different versions of the relationships lumped in English as “causal”:

event x1 physically causes event x2
event x1 is the justification for event x2
event x1 is the (human) motive for event x2
event x1 logically entails event x2

Each of these gismu has a related modal: ri'a, ki'u, mu'i, and ni'i respectively. Using these gismu and these modals, we can create various causal sentences with different implications:

Example 35
le spati cu banro ri'a le nu do djacu dunda fi le spati
The plant grows with-physical-cause the event-of you water give to the plant.
The plant grows because you water it.

Example 36
la djan. cpacu le pamoi se jinga ki'u le nu la djan. jinga
John gets the first prize with-justification the event-of John wins.
John got the first prize because he won.

Example 37
mi lebna le cukta mu'i le nu mi viska le cukta
I took the book with-motivation the event-of I saw the book.
I took the book because I saw it.

Example 38
la sokrates. morsi binxo ni'i le nu la sokrates. remna
Socrates dead-became with-logical-justification Socrates is-human.
Socrates died because Socrates is human.

In Example 35 through Example 36, the same English word “because” is used to translate all four modals, but the types of cause being expressed are quite different. Let us now focus on Example 35, and explore some variations on it.

As written, Example 35 claims that the plant grows, but only refers to the event of watering it in an abstraction bridi (abstractions are explained in Chapter 16) without actually making a claim. If I express Example 35, I have said that the plant in fact grows, but I have not said that you actually water it, merely that there is a causal relationship between watering and growing. This is semantically asymmetrical. Suppose I wanted to claim that the plant was being watered, and only mention its growth as ancillary information? Then we could reverse the main bridi and the abstraction bridi, saying:

Example 39
do djacu dunda fi le spati seri'a le nu ri banro
You water-give to the plant with-physical-effect it grows.
You water the plant; therefore, it grows.

with the ri'a changed to seri'a. In addition, there are also symmetrical forms:

Example 40
le nu do djacu dunda fi le spati cu rinka le nu le spati cu banro
The event-of (you water-give to the plant) causes the event-of (the plant grows).
Your watering the plant causes its growth. If you water the plant, then it grows.

does not claim either event, but asserts only the causal relationship between them. So in Example 40, I am not saying that the plant grows nor that you have in fact watered it. The second colloquial translation shows a form of “if-then” in English quite distinct from the logical connective “if-then” explained in Chapter ELG-ERROR in Template:Lch.

Suppose we wish to claim both events as well as their causal relationship? We can use one of two methods:

Example 41
le spati cu banro .iri'abo do djacu dunda fi le spati
The plant grows. Because you water-give to the plant.
The plant grows because you water it.

Example 42
do djacu dunda fi le spati .iseri'abo le spati cu banro
You water-give to the plant. Therefore it grows.
You water the plant; therefore, it grows.

The compound cmavo

.iri'abo and
.iseri'abo serve to connect two bridi, as the initial i indicates. The final bo is necessary to prevent the modal from “taking over” the following sumti. If the bo were omitted from Example 42 we would have:

Example 43
le spati cu banro .i ri'a do djacu dunda fi le spati
The plant grows. Because of you, [something] water-gives to the plant.
The plant grows. Because of you, water is given to the plant.


ri'a do is a modal sumti in Example 43, there is no longer an explicit sumti in the x1 place of
djacu dunda, and the translation must be changed.

The effect of sentences like Example 42 and Example 43 is that the modal, ri'a in this example, no longer modifies an explicit sumti. Instead, the sumti is implicit, the event given by a full bridi. Furthermore, there is a second implication: that the first bridi fills the x2 place of the gismu rinka; it specifies an event which is the effect. I am therefore claiming three things: that the plant grows, that you have watered it, and that there is a cause-and-effect relationship between the two.

In principle, any modal tag can appear in a sentence connective of the type exemplified by Example 42 and |Example 43. However, it makes little sense to use any modals which do not expect events or other abstractions to fill the places of the corresponding gismu. The sentence connective

.ibaubo is perfectly grammatical, but it is hard to imagine any two sentences which could be connected by an “in-language” modal. This is because a sentence describes an event, and an event can be a cause or an effect, but not a language.

Other modal connections

Like many Lojban grammatical constructions, sentence modal connection has both forethought and afterthought forms. (See Chapter ELG-ERROR in Template:Lch for a more detailed discussion of Lojban connectives.) Section 13.6 exemplifies only afterthought modal connection, illustrated here by:

Example 44
mi jgari lei djacu .iri'abo mi jgari le kabri
I grasp the-mass-of water with-physical-cause I grasp the cup.
Causing the mass of water to be grasped by me, I grasped the cup.
I grasp the water because I grasp the cup.

An afterthought connection is one that is signaled only by a cmavo (or a compound cmavo, in this case) between the two constructs being connected. Forethought connection uses a signal both before the first construct and between the two: the use of “both” and “and” in the first half of this sentence represents a forethought connection (though not a modal one).

To make forethought modal sentence connections in Lojban, place the modal plus gi before the first bridi, and gi between the two. No i is used within the construct. The forethought equivalent of Example is:

Example 45
ri'agi mi jgari le kabri gi mi jgari lei djacu
With-physical-cause I grasp the cup, I grasp the-mass-of water.
Because I grasp the cup, I grasp the water.

Note that the cause, the x1 of rinka is now placed first. To keep the two bridi in the original order of Example , we could say:

Example 46
seri'agi mi jgari lei djacu gi mi jgari le kabri
With-physical-effect I grasp the-mass-of water, I grasp the cup.

In English, the sentence “Therefore I grasp the water, I grasp the cup” is ungrammatical, because “therefore” is not grammatically equivalent to “because”. In Lojban,

seri'agi can be used just like

When the two bridi joined by a modal connection have one or more elements (selbri or sumti or both) in common, there are various condensed forms that can be used in place of full modal sentence connection with both bridi completely stated.

When the bridi are the same except for a single sumti, as in Examples 8.1 through 8.3, then a sumti modal connection may be employed:

Example 47
mi jgari ri'agi le kabri gi lei djacu
I grasp because the cup, the-mass-of water.Example means exactly the same as Example through Example , but there is no idiomatic English translation that will distinguish it from them.

If the two connected bridi are different in more than one sumti, then a termset may be employed. Termsets are explained more fully in Section 16.23, but are essentially a mechanism for creating connections between multiple sumti simultaneously.

Example 48
mi dunda le cukta la djan. .imu'ibo la djan. dunda lei jdini mi
I gave the book to John. Motivated-by John gave the-mass-of money to-me.
I gave the book to John, because John gave money to me.

means the same as:

Example 49
nu'i mu'igi la djan. lei jdini mi gi mi le cukta la djan. nu'u dunda
[start] because John, the-mass-of money, me; I, the book, John [end] gives.

Here there are three sumti in each half of the termset, because the two bridi share only their selbri.

There is no modal connection between selbri as such: bridi which differ only in the selbri can be modally connected using bridi-tail modal connection. The bridi-tail construct is more fully explained in Section 16.21, but essentially it consists of a selbri with optional sumti following it. Example is suitable for bridi-tail connection, and could be shortened to:

Example 50
mi mu'igi viska le cukta gi lebna le cukta
I, because saw the book, took the book.

Again, no straightforward English translation exists. It is even possible to shorten Example 50 further to:

Example 51
mi mu'igi viska gi lebna vau le cukta
I because saw, therefore took, the book.


le cukta is set off by the non-elidable vau and is made to belong to both bridi-tails – See Section 16.21 for more explanations.

Since this is a chapter on rearranging sumti, it is worth pointing out that Example 51 can be further rearranged to:

Example 52
mi le cukta mu'igi viska gi lebna
I, the book, because saw, therefore took.

which doesn't require the extra vau; all sumti before a conjunction of bridi-tails are shared.

Finally, mathematical operands can be modally connected.

Example 53
li ny. du li vo .ini'ibo li ny. du li re su'i re
the number n = the-number 4. Entailed-by the-number n = the-number 2 + 2.
n = 4 because n = 2 + 2.

can be reduced to:

Example 54
li ny. du li ni'igi vei re su'i re [ve'o] gi vo
the-number n = the-number because ( 2 + 2 ) therefore 4.
n is 2 + 2, and is thus 4.

The cmavo vei and ve'o represent mathematical parentheses, and are required so that

ni'igi affects more than just the immediately following operand, namely the first re. (The right parenthesis, ve'o, is an elidable terminator.) As usual, no English translation does Example justice.

Note: Due to restrictions on the Lojban parsing algorithm, it is not possible to form modal connectives using the

fi'o- plus-selbri form of modal. Only the predefined modals of selma'o BAI can be compounded as shown in Section 13.6 and Section 13.7.

Modal selbri

Consider the example:

Example 55
mi tavla bau la lojban. bai tu'a la frank.
I speak in-language Lojban with-compeller some-act-by Frank.
I speak in Lojban, under compulsion by Frank.

Example has two modal sumti, using the modals bau and bai. Suppose we wanted to specify the language explicitly but be vague about who's doing the compelling. We can simplify Example to:

Example 56
mi tavla bau la lojban. bai [ku].
I speak in-language Lojban under-compulsion.

In Example , the elidable terminator ku has taken the place of the sumti which would normally follow bai. Alternatively, we could specify the one who compels but keep the language vague:

Example 57
mi tavla bau [ku] bai tu'a la frank.
I speak in-some-language under-compulsion-by some-act-by Frank.

We are also free to move the modal-plus- ku around the bridi:

Example 58
bau [ku] bai ku mi tavla
In-some-language under-compulsion I speak.

An alternative to using ku is to place the modal cmavo right before the selbri, following the cu which often appears there. When a modal is present, the cu is almost never necessary.

Example 59
mi bai tavla bau la lojban.
I compelledly speak in-language Lojban.

In this use, the modal is like a tanru modifier semantically, although grammatically it is quite distinct. Example 59 is very similar in meaning to:

Example 60
mi se bapli tavla bau la lojban.
I compelledly-speak in-language Lojban.

The se conversion is needed because

bapli tavla would be a “compeller type of speaker” rather than a “compelled (by someone) type of speaker”, which is what a
bai tavla is.

If the modal preceding a selbri is constructed using fi'o, then fe'u is required to prevent the main selbri and the modal selbri from colliding:

Example 61
mi fi'o kanla fe'u viska do
I with-eye see you.
I see you with my eye(s).

There are two other uses of modals. A modal can be attached to a pair of bridi-tails that have already been connected by a logical, non-logical, or modal connection (See Chapter ELG-ERROR in Template:Lch for more on logical and non-logical connections):

Example 62
mi bai ke ge klama le zarci gi cadzu le bisli [ke'e]
I under-compulsion (both go to-the market and walk on-the ice).
Under compulsion, I both go to the market and walk on the ice.

Here the bai is spread over both

klama le zarci and
cadzu le bisli, and the
ge ... gi represents the logical connection “both-and” between the two.

Similarly, a modal can be attached to multiple sentences that have been combined with tu'e and tu'u, which are explained in more detail in Section 18.45:

Example 63
bai tu'e mi klama le zarci .i mi cadzu le bisli [tu'u]
Under-compulsion [start] I go to-the market. I walk on-the ice [end].

means the same thing as Example .

Note: Either BAI modals or

fi'o- plus-selbri modals may correctly be used in any of the constructions discussed in this section.

Modal relative phrases; Comparison

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
pe GOI restrictive relative phrase
ne GOI incidental relative phrase
mau BAI zmadu modal
me'a BAI mleca modal

Relative phrases and clauses are explained in much more detail in Chapter 12. However, there is a construction which combines a modal with a relative phrase which is relevant to this chapter. Consider the following examples of relative clauses:

Example 64
la .apasionatas. poi se cusku la .artr. rubnstain. cu se nelci mi
The Appassionata which is-expressed-by Arthur Rubinstein is-liked-by me.

Example 65
la .apasionatas. noi se finti la betovn. cu se nelci mi
The Appassionata, which is-created-by Beethoven, is-liked-by me.

In Example 64, :la .apasionatas. refers to a particular performance of the sonata, namely the one performed by Rubinstein. Therefore, the relative clause :poi se cusku uses the cmavo poi (of selma'o NOI) to restrict the meaning of :la .apasionatas to the performance in question.

In Example 65, however, :la .apasionatas. refers to the sonata as a whole, and the information that it was composed by Beethoven is merely incidental. The cmavo noi (also of selma'o NOI) expresses the incidental nature of this relationship.

The cmavo pe and ne (of selma'o GOI) are roughly equivalent to poi and noi respectively, but are followed by sumti rather than full bridi. We can abbreviate Example 64 and Example 65 to:

Example 66
la .apasionatas. pe la .artr. rubnstain. se nelci mi
The Appassionata of Arthur Rubinstein is-liked-by me.

Example 67
la .apasionatas. ne la betovn. se nelci mi
The Appassionata, which is of Beethoven, is-liked-by me.

Here the precise selbri of the relative clauses is lost: all we can tell is that the Appassionata is connected in some way with Rubinstein (in Example 66) and Beethoven (in Example 67), and that the relationships are respectively restrictive and incidental.

It happens that both cusku and finti have BAI cmavo, namely cu'u and fi'e. We can recast Example 66 and Example 67 as:

Example 68
la .apasionatas pe cu'u la .artr. rubnstain. cu se nelci mi
The Appassionata expressed-by Arthur Rubinstein is-liked-by me.

Example 69
la .apasionatas ne fi'e la betovn. cu se nelci mi
The Appassionata, invented-by Beethoven, is-liked-by me.

Example 68 and Example 69 have the full semantic content of Example 66 and Example 67 respectively.

Modal relative phrases are often used with the BAI cmavo mau and me'a, which are based on the comparative gismu zmadu (more than) and mleca (less than) respectively. The place structures are:

Example 70
x1 is more than x2 in property/quantity x3 by amount x4
x1 is less than x2 in property/quantity x3 by amount x4

Here are some examples:

Example 71
la frank. nelci la betis. ne semau la meiris.
Frank likes Betty, which-is more-than Mary.
Frank likes Betty more than (he likes) Mary.

Example 71 requires that Frank likes Betty, but adds the information that his liking for Betty exceeds his liking for Mary. The modal appears in the form semau because the x2 place of zmadu is the basis for comparison: in this case, Frank's liking for Mary.

Example 72
la frank. nelci la meiris. ne seme'a la betis.
Frank likes Mary, which-is less-than Betty.
Frank likes Mary less than (he likes) Betty.

Here we are told that Frank likes Mary less than he likes Betty; the information about the comparison is the same. It would be possible to rephrase Example using me'a rather than semau, and Example using mau rather than seme'a, but such usage would be unnecessarily confusing. Like many BAI cmavo, mau and me'a are more useful when converted with se.

If the ne were omitted in Example and Example , the modal sumti (:la meiris. and :la betis. respectively) would become attached to the bridi as a whole, producing a very different translation. Example would become:

Example 73
la frank. nelci la meiris. seme'a la betis.
Frank likes Mary is-less-than Betty.
Frank's liking Mary is less than Betty.

which compares a liking with a person, and is therefore nonsense.

Pure comparison, which states only the comparative information but says nothing about whether Frank actually likes either Mary or Betty (he may like neither, but dislike Betty less), would be expressed differently, as:

Example 74
le ni la frank. nelci la betis. cu zmadu le ni la frank. nelci la meiris.
The quantity-of Frank's liking Betty is-more-than the quantity-of Frank's liking Mary.

The mechanisms explained in this section are appropriate to many modals other than semau and seme'a. Some other modals that are often associated with relative phrases are: seba'i (“instead of”), ci'u (“on scale”), de'i ( “dated”), du'i ( “as much as”).

Some BAI tags can be used equally well in relative phrases or attached to bridi; others seem useful only attached to bridi. But it is also possible that the usefulness of particular BAI modals is an English-speaker bias, and that speakers of other languages may find other BAIs useful in divergent ways.

Note: The uses of modals discussed in this section are applicable both to BAI modals and to fi'o-plus-selbri modals.

Mixed modal connection

It is possible to mix logical connection (explained in Chapter ELG-ERROR in Template:Lch) with modal connection, in a way that simultaneously asserts the logical connection and the modal relationship. Consider the sentences:

Example 75
mi nelci do .ije mi nelci la djein.
I like you. And I like Jane.

which is a logical connection, and

Example 76
mi nelci do .iki'ubo mi nelci la djein.
I like you. Justified-by I like Jane.

The meanings of Example 75 and Example 76 can be simultaneously expressed by combining the two compound cmavo, thus:

Example 77
mi nelci do .ijeki'ubo mi nelci la djein.
I like you. And justified-by I like Jane.

Here the two sentences

mi nelci do and :mi nelci la djein. are simultaneously asserted, their logical connection is asserted, and their causal relationship is asserted. The logical connective je comes before the modal ki'u in all such mixed connections.


mi nelci do and :mi nelci la djein. differ only in the final sumti, we can transform Example into a mixed sumti connection:

Example 78
mi nelci do .eki'ubo la djein.
I like you and/because Jane.

Note that this connection is an afterthought one. Mixed connectives are always afterthought; forethought connectives must be either logical or modal.

There are numerous other afterthought logical and non-logical connectives that can have modal information planted within them. For example, a bridi-tail connected version of Example 78 would be:

Example 79
mi nelci do gi'eki'ubo nelci la djein.
I like you and/because like Jane.

The following three complex examples all mean the same thing.

Example 80
mi bevri le dakli .ijeseri'abo tu'e mi bevri le gerku .ijadu'ibo mi bevri le mlatu [tu'u]
I carry the sack. And [effect] (I carry the dog. And/or [equal] I carry the cat.)
I carry the sack. As a result I carry the dog or I carry the cat, equally.

Example 81
mi bevri le dakli gi'eseri'ake bevri le gerku gi'adu'ibo bevri le mlatu [ke'e]
I carry the sack and [effect] (carry the dog and/or [equal] carry the cat).
I carry the sack and as a result carry the dog or carry the cat equally.

Example 82
mi bevri le dakli .eseri'ake le gerku .adu'ibo le mlatu [ke'e]
I carry the sack and [effect] (the cat and/or [equal] the dog).
I carry the sack, and as a result the cat or the dog equally.

In Example , the tu'etu'u brackets are the equivalent of the keke'e brackets in Example and Example , because keke'e cannot extend across more than one sentence. It would also be possible to change the

.ijeseri'abo to
.ije seri'a, which would show that the tu'etu'u portion was an effect, but would not pin down the
mi bevri le dakli portion as the cause. It is legal for a modal (or a tense; See Chapter 14) to modify the whole of a tu'etu'u construct.

Note: The uses of modals discussed in this section are applicable both to BAI modals and to

fi'o- plus-selbri modals.

Modal conversion: JAI

The following cmavo are discussed in this section:

cmavo selma'o subclass meaning
jai JAI modal conversion
fai FA modal place structure tag

So far, conversion of numbered bridi places with SE and the addition of modal places with BAI have been two entirely separate operations. However, it is possible to convert a selbri in such a way that, rather than exchanging two numbered places, a modal place is made into a numbered place. For example,

Example 83
mi cusku bau la lojban.
I express [something] in-language Lojban.

has an explicit x1 place occupied by mi and an explicit bau place occupied by

la lojban. To exchange these two, we use a modal conversion operator consisting of

jai (of selma'o JAI) followed by the modal cmavo. Thus, the modal conversion of Example 83 is:

Example 84
la lojban. jai bau cusku fai mi
Lojban is-the-language-of-expression used-by me.

In Example 84, the modal place

la lojban. has become the x1 place of the new selbri
jai bau cusku. What has happened to the old x1 place? There is no numbered place for it to move to, so it moves to a special “unnumbered place” marked by the tag fai of selma'o FA.

Note: For the purposes of place numbering, fai behaves like fi'a; it does not affect the numbering of the other places around it.

Like SE conversions, JAI conversions are especially convenient in descriptions. We may refer to “the language of an expression” as

le jai bau cusku, for example.

In addition, it is grammatical to use jai without a following modal. This usage is not related to modals, but is explained here for completeness. The effect of jai by itself is to send the x1 place, which should be an abstraction, into the fai position, and to raise one of the sumti from the abstract sub-bridi into the x1 place of the main bridi. This feature is discussed in more detail in Section 16.9. The following two examples mean the same thing:

Example 85
le nu mi lebna le cukta cu se krinu le nu mi viska le cukta
The event-of (I take the book) is-justified-by the event-of (I see the book).
My taking the book is justified by my seeing it.

Example 86
mi jai se krinu le nu mi viska le cukta kei [fai le nu mi lebna le cukta]
I am-justified by the event-of (I see the book) [namely, the event-of (I take the book)]
I am justified in taking the book by seeing the book.

Example 86, with the bracketed part omitted, allows us to say that “I am justified” whereas in fact it is my action that is justified. This construction is vague, but useful in representing natural-language methods of expression.

Note: The uses of modals discussed in this section are applicable both to BAI modals and to :fi'o- plus-selbri modals.

Modal negation

Negation is explained in detail in Chapter ELG-ERROR in Template:Lch. There are two forms of negation in Lojban: contradictory and scalar negation. Contradictory negation expresses what is false, whereas scalar negation says that some alternative to what has been stated is true. A simple example is the difference between “John didn't go to Paris” (contradictory negation) and “John went to (somewhere) other than Paris” (scalar negation).

Contradictory negation involving BAI cmavo is performed by appending :-nai (of selma'o NAI) to the BAI. A common use of modals with :-nai is to deny a causal relationship:

Example 87
mi nelci do mu'inai le nu do nelci mi
I like you, but not because you like me.

Example 87 denies that the relationship between my liking you (which is asserted) and your liking me (which is not asserted) is one of motivation. Nothing is said about whether you like me or not, merely that that hypothetical liking is not the motivation for my liking you.

Scalar negation is achieved by prefixing na'e (of selma'o NAhE), or any of the other cmavo of NAhE, to the BAI cmavo.

Example 88
le spati cu banro na'emu'i le nu do djacu dunda fi le spati
The plant grows other-than-motivated-by the event-of you water-give to the plant.

Example 88 says that the relationship between the plant's growth and your watering it is not one of motivation: the plant is not motivated to grow, as plants are not something which can have motivation as a rule. Implicitly, some other relationship between watering and growth exists, but Example 88 doesn't say what it is (presumably ri'a).

Note: Modals made with fi'o plus a selbri cannot be negated directly. The selbri can itself be negated either with contradictory or with scalar negation, however.

Sticky modals

The following cmavo is discussed in this section:

cmavo selma'o subclass meaning
KI|stickiness flag

Like tenses, modals can be made persistent from the bridi in which they appear to all following bridi. The effect of this “stickiness” is to make the modal, along with its following sumti, act as if it appeared in every successive bridi. Stickiness is put into effect by following the modal (but not any following sumti) with the cmavo ki of selma'o KI. For example,

Example 89
mi tavla bau la lojban. bai ki tu'a la frank. .ibabo mi tavla bau la gliban.
I speak in-language Lojban compelled-by some-property-of Frank. Afterward, I speak in-language English.

means the same as:

Example 90
mi tavla bau la lojban. bai tu'a la frank. .ibabo mi tavla bau la gliban. bai tu'a la frank.
I speak in-language Lojban compelled-by some-property-of Frank. Afterward, I speak in-language English compelled-by some-property-of Frank.

In Example 89, bai is made sticky, and so Frank's compelling is made applicable to every following bridi. bau is not sticky, and so the language may vary from bridi to bridi, and if not specified in a particular bridi, no assumption can safely be made about its value.

To cancel stickiness, use the form :BAI ki ku, which stops any modal value for the specified BAI from being passed to the next bridi. To cancel stickiness for all modals simultaneously, and also for any sticky tenses that exist ( ki is used for both modals and tenses), use ki by itself, either before the selbri or (in the form :ki ku) anywhere in the bridi:

Example 91
mi ki tavla
I speak (no implication about language or compulsion).

Note: Modals made with fi'o-plus-selbri cannot be made sticky. This is an unfortunate, but unavoidable, restriction.

Logical and non-logical connection of modals

Logical and non-logical connectives are explained in detail in Chapter ELG-ERROR in Template:Lch. For the purposes of this chapter, it suffices to point out that a logical (or non-logical) connection between two bridi which differ only in a modal can be reduced to a single bridi with a connective between the modals. As a result, Example 92 and Example 93 mean the same thing:

Example 92
la frank. bajra seka'a le zdani .ije la frank. bajra teka'a le zdani
Frank runs with-destination the house. And Frank runs with-origin the house.
Frank runs to the house, and Frank runs from the house.

Example 93
la frank. bajra seka'a je teka'a le zdani
Frank runs with-destination and with-origin the house.
Frank runs to and from the house.

Neither example implies whether a single act, or two acts, of running is referred to. To compel the sentence to refer to a single act of running, you can use the form:

Example 94
la frank. bajra seka'a le zdani ce'e teka'a le zdani
Frank runs with-destination the house [joined-to] with-origin the-house.

The cmavo ce'e creates a termset containing two terms (termsets are explained in Chapter ELG-ERROR in Template:Lch and Chapter 17). When a termset contains more than one modal tag derived from a single BAI, the convention is that the two tags are derived from a common event.

CV'V cmavo of selma'o BAI with irregular forms

There are 65 cmavo of selma'o BAI, of which all but one ( do'e, discussed in Section 13.5), are derived directly from selected gismu. Of these 64 cmavo, 36 are entirely regular and have the form CV'V, where C is the first consonant of the corresponding gismu, and the Vs are the two vowels of the gismu. The remaining BAI cmavo, which are irregular in one way or another, are listed in the table below. The table is divided into sub-tables according to the nature of the exception; some cmavo appear in more than one sub-table, and are so noted.

cmavo gismu comments
Monosyllables of the form CVV:
bai bapli
bau bangu
cau claxu
fau fasnu
gau gasnu
kai ckaji uses 2nd consonant of gismu
mau zmadu uses 2nd consonant of gismu
koi korbi
rai traji uses 2nd consonant of gismu
sau sarcu
tai tamsmi based on lujvo, not gismu
zau zanru
Second consonant of the gismu as the C:
(the gismu is always of the form CCVCV)
ga'a zgana
kai ckaji has CVV form (monosyllable)
ki'i ckini
la'u klani has irregular 2nd V
le'a klesi has irregular 2nd V
mau zmadu has CVV form (monosyllable)
me'e cmene
ra'a srana
ra'i krasi
rai traji has CVV form (monosyllable)
ti'i stidi
tu'i stuzi
Irregular 2nd V:
fi'e finti
la'u klani uses 2nd consonant of gismu
le'a klesi uses 2nd consonant of gismu
ma'e marji
mu'u mupli
ti'u tcika
va'o vanbi
Special cases:
ri'i lifri uses 3rd consonant of gismu
tai tamsmi based on lujvo, not gismu
va'u xamgu CV'V cmavo can’t begin with “x”

Complete table of BAI cmavo with rough English equivalents

The following table shows all the cmavo belonging to selma'o BAI, and has five columns. The first column is the cmavo itself; the second column is the gismu linked to it. The third column gives an English phrase which indicates the meaning of the cmavo; and the fourth column indicates its meaning when preceded by se.

For those cmavo with meaningful te, ve, and even xe conversions (depending on the number of places of the underlying gismu), the meanings of these are shown on one or two extra columns following the meaning column for that cmavo.

It should be emphasized that the place structures of the gismu control the meanings of the BAI cmavo. The English phrases shown here are only suggestive, and are often too broad or too narrow to correctly specify what the acceptable range of uses for the modal tag are.

cmavo selma'o subclass meaning
ba'i basti replaced by instead of
bai bapli compelled by compelling
bau bangu in language in language of
be'i benji sent by transmitting te=sent to ve=with transmit origin xe=transmitted via
ca'i catni by authority of with authority over
cau claxu lacked by without
ci'e ciste in system with system function te=of system components
ci'o cinmo felt by feeling emotion
ci'u ckilu on the scale on scale measuring
cu'u cusku as said by expressing te=as told to ve=expressed in medium
de'i detri dated on the same date as
di'o diklo at the locus of at specific locus
do'e ----- vaguely related to
du'i dunli as much as equal to
du'o djuno according to knowing facts te=knowing about ve=under epistemology
fa'e fatne reverse of in reversal of
fau fasnu in the event of
fi'e finti created by creating work te=created for purpose
ga'a zgana to observer observing te=observed by means ve=observed under conditions
gau gasnu with agent as agent in doing
ja'e jalge resulting in results because of
ja'i javni by rule by rule prescribing
ji'e jimte up to limit as a limit of
ji'o jitro under direction controlling
ji'u jicmu based on supporting
ka'a klama gone to by with destination te=with origin ve=via route xe=by transport mode
ka'i krati represented by on behalf of
kai ckaji characterizing with property
ki'i ckini as relation of related to te=with relation
ki'u krinu justified by with justified result
koi korbi bounded by as boundary of te=bordering
ku'u kulnu in culture in culture of
la'u klani as quantity of in quantity
le'a klesi in category as category of te=defined by quality
li'e lidne led by leading
ma'e marji of material made from material te=in material form of
ma'i manri in reference frame as a standard for
mau zmadu exceeded by more than
me'a mleca undercut by less than
me'e cmene with name as a name for te=as a name to
mu'i mukti motivated by motive therefore
mu'u mupli exemplified by as an example of
ni'i nibli entailed by entails
pa'a panra in addition to similar to te=similar in pattern ve=similar by standard
pa'u pagbu with component as a part of
pi'o pilno used by using tool
po'i porsi in the sequence sequenced by rule
pu'a pluka pleased by in order to please
pu'e pruce by process processing from te=processing into ve=passing through stages
ra'a srana pertained to by concerning
ra'i krasi from source as an origin of
rai traji with superlative superlative in te=at extreme ve=superlative among
ri'a rinka caused by causing
ri'i lifri experienced by experiencing
sau sarcu requiring necessarily for te=necessarily under conditions
si'u sidju aided by assisting in
ta'i tadji by method as a method for
tai tamsmi as a form of in form te=in form similar to
ti'i stidi suggested by suggesting te=suggested to
ti'u tcika with time at the time of
tu'i stuzi with site as location of
va'o vanbi under conditions as conditions for
va'u xamgu benefiting from with beneficiary
zau zanru approved by approving
zu'e zukte with actor with means to goal te=with goal

The lujvo tamsmi on which tai is based is derived from the tanru tarmi simsa and has the place structure:

tamsmi = x1 has form x2, similar in form to x3 in property/quality x4

This lujvo is employed because tarmi does not have a place structure useful for the modal's purpose.

Time and space


This chapter attempts to document and explain the space/time tense system of Lojban. It does not attempt to answer all questions of the form “How do I say such-and-such (an English tense) in Lojban?” Instead, it explores the Lojban tense system from the inside, attempting to educate the reader into a Lojbanic viewpoint. Once the overall system is understood and the resources that it makes available are familiar, the reader should have some hope of using appropriate tense constructs and being correctly understood.

The system of Lojban tenses presented here may seem really complex because of all the pieces and all the options; indeed, this chapter is the longest one in this book. But tense is in fact complex in every language. In your native language, the subtleties of tense are intuitive. In foreign languages, you are seldom taught the entire system until you have reached an advanced level. Lojban tenses are extremely systematic and productive, allowing you to express subtleties based on what they mean rather than on how they act similarly to English tenses. This chapter concentrates on presenting an intuitive approach to the meaning of Lojban tense words and how they may be creatively and productively combined.

What is “tense”? Historically, “tense” is the attribute of verbs in English and related languages that expresses the time of the action. In English, three tenses are traditionally recognized, conventionally called the past, the present, and the future. There are also a variety of compound tenses used in English. However, there is no simple relationship between the form of an English tense and the time actually expressed:

I go to London tomorrow.
I will go to London tomorrow.
I am going to London tomorrow.

all mean the same thing, even though the first sentence uses the present tense; the second, the future tense; and the third, a compound tense usually called “present progressive”. Likewise, a newspaper headline says “JONES DIES”, although it is obvious that the time referred to must be in the past. Tense is a mandatory category of English: every sentence must be marked for tense, even if in a way contrary to logic, because every main verb has a tense marker built into to it. By contrast, Lojban brivla have no implicit tense marker attached to them.

In Lojban, the concept of tense extends to every selbri, not merely the verb-like ones. In addition, tense structures provide information about location in space as well as in time. All tense information is optional in Lojban: a sentence like:

Example 14.1:

mi klama le zarci
I go-to the market.

can be understood as:

I went to the market.
I am going to the market.
I have gone to the market.
I will go to the market.
I continually go to the market.

as well as many other possibilities: context resolves which is correct.

The placement of a tense construct within a Lojban bridi is easy: right before the selbri. It goes immediately after the cu, and can in fact always replace the cu (although in very complex sentences the rules for eliding terminators may be changed as a result). In the following examples, pu is the tense marker for “past time”:

Example 14.2:

mi cu pu klama le zarci
mi pu klama le zarci
I in-the-past go-to the market.
I went to the market.

It is also possible to put the tense somewhere else in the bridi by adding ku after it. This ku is an elidable terminator, but it's almost never possible to actually elide it except at the end of the bridi:

Example 14.3:

puku mi klama le zarci
In-the-past I go-to the market.
Earlier, I went to the market.
Example 14.4:

mi klama puku le zarci
I go-to in-the-past the market.
I went earlier to the market.
Example 14.5:

mi klama le zarci pu [ku]
I go-to the market in-the-past.
I went to the market earlier.

Example 14.2 through Example 14.5 are different only in emphasis. Abnormal order, such as Example 14.3 through Example 14.5 exhibit, adds emphasis to the words that have been moved; in this case, the tense cmavo pu. Words at either end of the sentence tend to be more noticeable.

Spatial tenses: FAhA and VA

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning vi VA short distance va VA medium distance vu VA long distance

zu'a FAhA left ri'u FAhA right ga'u FAhA up ni'a FAhA down ca'u FAhA front ne'i FAhA within be'a FAhA north of </tab>

(The complete list of FAhA cmavo can be found in Section 14.26.)

Why is this section about spatial tenses rather than the more familiar time tenses of Section , asks the reader? Because the model to be used in explaining both will be easier to grasp for space than for time. The explanation of time tenses will resume in Section 14.3.

English doesn't have mandatory spatial tenses. Although there are plenty of ways in English of showing where an event happens, there is absolutely no need to do so. Considering this fact may give the reader a feel for what the optional Lojban time tenses are like. From the Lojban point of view, space and time are interchangeable, although they are not treated identically.

Lojban specifies the spatial tense of a bridi (the place at which it occurs) by using words from selma'o FAhA and VA to describe an imaginary journey from the speaker to the place referred to. FAhA cmavo specify the direction taken in the journey, whereas VA cmavo specify the distance gone. For example:

Example 14.6:

le nanmu va batci le gerku
The man [medium distance] bites the dog.
Over there the man is biting the dog.

What is at a medium distance? The event referred to by the bridi: the man biting the dog. What is this event at a medium distance from? The speaker's location. We can understand the va as saying: “If you want to get from the speaker's location to the location of the bridi, journey for a medium distance (in some direction unspecified).” This “imaginary journey” can be used to understand not only Example 14.6, but also every other spatial tense construct.

Suppose you specify a direction with a FAhA cmavo, rather than a distance with a VA cmavo:

Example 14.7:

le nanmu zu'a batci le gerku
The man [left] bites the dog.

Here the imaginary journey is again from the speaker's location to the location of the bridi, but it is now performed by going to the left (in the speaker's reference frame) for an unspecified distance. So a reasonable translation is:

To my left, the man bites the dog.

The “my” does not have an explicit equivalent in the Lojban, because the speaker's location is understood as the starting point.

(Etymologically, by the way, zu'a is derived from zunle, the gismu for “left”, whereas vi, va, and vu are intended to be reminiscent of ti, ta, and tu, the demonstrative pronouns “this-here”, “that-there”, and “that-yonder”.)

What about specifying both a direction and a distance? The rule here is that the direction must come before the distance:

Example 14.8:

le nanmu zu'avi batci le gerku
The man [left] [short distance] bites the dog.
Slightly to my left, the man bites the dog.

As explained in Section , it would be perfectly correct to use ku to move this tense to the beginning or the end of the sentence to emphasize it:

Example 14.9:

zu'aviku le nanmu cu batci le gerku
[Left] [short distance] the man bites the dog.
Slightly to my left, the man bites the dog.

Compound spatial tenses

Humph, says the reader: this talk of “imaginary journeys” is all very well, but what's the point of it? – zu'a means “on the left” and vi means “nearby”, and there's no more to be said. The imaginary-journey model becomes more useful when so-called compound tenses are involved. A compound tense is exactly like a simple tense, but has several FAhAs run together:

Example 14.10:

le nanmu ga'u zu'a batci le gerku
The man [up] [left] bites the dog.

The proper interpretation of Example 14.10 is that the imaginary journey has two stages: first move from the speaker's location upward, and then to the left. A translation might read:

Left of a place above me, the man bites the dog.

(Perhaps the speaker is at the bottom of a manhole, and the dog-biting is going on at the edge of the street.)

In the English translation, the keywords “left” and “above” occur in reverse order to the Lojban order. This effect is typical of what happens when we “unfold” Lojban compound tenses into their English equivalents, and shows why it is not very useful to try to memorize a list of Lojban tense constructs and their colloquial English equivalents.

The opposite order also makes sense:

Example 14.11:

le nanmu zu'a ga'u batci le gerku
The man [left] [up] bites the dog.
Above a place to the left of me, the man bites the dog.

In ordinary space, the result of going up and then to the left is the same as that of going left and then up, but such a simple relationship does not apply in all environments or to all directions: going south, then east, then north may return one to the starting point, if that point is the North Pole.

Each direction can have a distance following:

Example 14.12:

le nanmu zu'avi ga'uvu batci le gerku
The man [left] [short distance] [up] [long distance] bites the dog.
Far above a place slightly to the left of me, the man bites the dog.

A distance can also come at the beginning of the tense construct, without any specified direction. ( Example 14.6, with VA alone, is really a special case of this rule when no directions at all follow.)

Example 14.13:

le nanmu vi zu'a batci le gerku
The man [short distance] [left] bites the dog.
Left of a place near me, the man bites the dog.

Any number of directions may be used in a compound tense, with or without specified distances for each:

Example 14.14:

le nanmu ca'uvi ni'ava ri'uvu ne'i batci le gerku
The man [front] [short] [down] [medium] [right] [long] [within] bites the dog.
Within a place a long distance to the right of a place which is a medium distance downward from a place a short distance in front of me, the man bites the dog.

Whew! It's a good thing tense constructs are optional: having to say all that could certainly be painful. Note, however, how much shorter the Lojban version of Example 14.14 is than the English version.

Temporal tenses: PU and ZI

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning pu PU past ca PU present ba PU future

zi ZI short time distance za ZI medium time distance zu ZI long time distance </tab>

Now that the reader understands spatial tenses, there are only two main facts to understand about temporal tenses: they work exactly like the spatial tenses, with selma'o PU and ZI standing in for FAhA and VA; and when both spatial and temporal tense cmavo are given in a single tense construct, the temporal tense is expressed first. (If space could be expressed before or after time at will, then certain constructions would be ambiguous.)

Example 14.15:

le nanmu pu batci le gerku
The man [past] bites the dog.
The man bit the dog.

means that to reach the dog-biting, you must take an imaginary journey through time, moving towards the past an unspecified distance. (Of course, this journey is even more imaginary than the ones talked about in the previous sections, since time-travel is not an available option.)

Lojban recognizes three temporal directions: pu for the past, ca for the present, and ba for the future. (Etymologically, these derive from the corresponding gismu purci, cabna, and balvi. See Section 14.22 for an explanation of the exact relationship between the cmavo and the gismu.) There are many more spatial directions, since there are FAhA cmavo for both absolute and relative directions as well as “direction-like relationships” like “surrounding”, “within”, “touching”, etc. (See Section 14.26 for a complete list.) But there are really only two directions in time: forward and backward, toward the future and toward the past. Why, then, are there three cmavo of selma'o PU?

The reason is that tense is subjective: human beings perceive space and time in a way that does not necessarily agree with objective measurements. We have a sense of “now” which includes part of the objective past and part of the objective future, and so we naturally segment the time line into three parts. The Lojban design recognizes this human reality by providing a separate time-direction cmavo for the “zero direction”, Similarly, there is a FAhA cmavo for the zero space direction: bu'u, which means something like “coinciding”.

(Technical note for readers conversant with relativity theory: The Lojban time tenses reflect time as seen by the speaker, who is assumed to be a “point-like observer” in the relativistic sense: they do not say anything about physical relationships of relativistic interval, still less about implicit causality. The nature of tense is not only subjective but also observer-based.)

Here are some examples of temporal tenses:

Example 14.16:

le nanmu puzi batci le gerku
The man [past] [short distance] bites the dog.
A short time ago, the man bit the dog.
Example 14.17:

le nanmu pu pu batci le gerku
The man [past] [past] bites the dog.
Earlier than an earlier time than now, the man bit the dog.
The man had bitten the dog.
The man had been biting the dog.
Example 14.18:

le nanmu ba puzi batci le gerku
The man [future] [past] [short] bites the dog.
Shortly earlier than some time later than now, the man will bite the dog.
Soon before then, the man will have bitten the dog.
The man will have just bitten the dog.
The man will just have been biting the dog.

What about the analogue of an initial VA without a direction? Lojban does allow an initial ZI with or without following PUs:

Example 14.19:

le nanmu zi pu batci le gerku
The man [short] [past] bites the dog.
Before a short time from or before now, the man bit or will bite the dog.
Example 14.20:

le nanmu zu batci le gerku
The man [long] bites the dog.
A long time from or before now, the man will bite or bit the dog.

Example 14.19 and Example 14.20 are perfectly legitimate, but may not be very much used: zi by itself signals an event that happens at a time close to the present, but without saying whether it is in the past or the future. A rough translation might be “about now, but not exactly now”.

Because we can move in any direction in space, we are comfortable with the idea of events happening in an unspecified space direction ( “nearby” or “far away”), but we live only from past to future, and the idea of an event which happens “nearby in time” is a peculiar one. Lojban provides lots of such possibilities that don't seem all that useful to English-speakers, even though you can put them together productively; this fact may be a limitation of English.

Finally, here are examples which combine temporal and spatial tense:

Example 14.21:

le nanmu puzu vu batci le gerku
The man [past] [long time] [long space] bites the dog.
Long ago and far away, the man bit the dog.


Example 14.22:

le nanmu batci le gerku puzuvuku
The man bites the dog [past] [long time] [long space].
The man bit the dog long ago and far away.

Interval sizes: VEhA and ZEhA

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ve'i VEhA short space interval ve'a VEhA medium space interval ve'u VEhA long space interval

ze'i ZEhA short time interval ze'a ZEhA medium time interval ze'u ZEhA long time interval </tab>

So far, we have considered only events that are usually thought of as happening at a particular point in space and time: a man biting a dog at a specified place and time. But Lojbanic events may be much more “spread out” than that:

mi vasxu (I breathe) is something which is true during the whole of my life from birth to death, and over the entire part of the earth where I spend my life. The cmavo of VEhA (for space) and ZEhA (for time) can be added to any of the tense constructs we have already studied to specify the size of the space or length of the time over which the bridi is claimed to be true.
Example 14.23:

le verba ve'i cadzu le bisli
The child [small space interval] walks-on the ice.
In a small space, the child walks on the ice.
The child walks about a small area of the ice.

means that her walking was done in a small area. Like the distances, the interval sizes are classified only roughly as “small, medium, large”, and are relative to the context: a small part of a room might be a large part of a table in that room.

Here is an example using a time interval:

Example 14.24:

le verba ze'a cadzu le bisli
The child [medium time interval] walks-on the ice.
For a medium time, the child walks/walked/will walk on the ice.

Note that with no time direction word, Example 14.24 does not say when the walking happened: that would be determined by context. It is possible to specify both directions or distances and an interval, in which case the interval always comes afterward:

Example 14.25:

le verba pu ze'a cadzu le bisli
The child [past] [medium time interval] walks-on the ice.
For a medium time, the child walked on the ice.
The child walked on the ice for a while.

In Example 14.25, the relationship of the interval to the specified point in time or space is indeterminate. Does the interval start at the point, end at the point, or is it centered on the point? By adding an additional direction cmavo after the interval, this question can be conclusively answered:

Example 14.26:

mi ca ze'ica cusku dei
I [present] [short time interval - present] express this-utterance.
I am now saying this sentence.

means that for an interval starting a short time in the past and extending to a short time in the future, I am expressing the utterance which is Example 14.26. Of course, “short” is relative, as always in tenses. Even a long sentence takes up only a short part of a whole day; in a geological context, the era of <emphasis>Homo sapiens</emphasis> would only be a ze'i interval.

By contrast,

Example 14.27:

mi ca ze'ipu cusku dei
I [present] [short time interval - past] express this-utterance.
I have just been saying this sentence.

means that for a short time interval extending from the past to the present I have been expressing Example 14.27. Here the imaginary journey starts at the present, lays down one end point of the interval, moves into the past, and lays down the other endpoint. Another example:

Example 14.28:

mi pu ze'aba citka le mi sanmi
I [past] [medium time interval - future] eat my meal.
For a medium time afterward, I ate my meal.
I ate my meal for a while.

With ca instead of ba, Example 14.28 becomes Example 14.29,

Example 14.29:

mi pu ze'aca citka le mi sanmi
I [past] [medium time interval - present] eat my meal.
For a medium time before and afterward, I ate my meal.
I ate my meal for a while.

because the interval would then be centered on the past moment rather than oriented toward the future of that moment. The colloquial English translations are the same – English is not well-suited to representing this distinction.

Here are some examples of the use of space intervals with and without specified directions:

Example 14.30:

ta ri'u ve'i finpe
That-there [right] [short space interval] is-a-fish.
That thing on my right is a fish.

In Example 14.30, there is no equivalent in the colloquial English translation of the “small interval” which the fish occupies. Neither the Lojban nor the English expresses the orientation of the fish. Compare Example 14.31:

Example 14.31:

ta ri'u ve'ica'u finpe
That-there [right] [short space interval - front] is-a-fish.
That thing on my right extending forwards is a fish.

Here the space interval occupied by the fish extends from a point on my right to another point in front of the first point.

Vague intervals and non-specific tenses

What is the significance of failing to specify an interval size of the type discussed in Section 14.4? The Lojban rule is that if no interval size is given, the size of the space or time interval is left vague by the speaker. For example:

Example 14.32:

mi pu klama le zarci
I [past] go-to the market.

really means:

At a moment in the past, and possibly other moments as well, the event “I went to the market” was in progress.

The vague or unspecified interval contains an instant in the speaker's past. However, there is no indication whether or not the whole interval is in the speaker's past! It is entirely possible that the interval during which the going-to-the-market is happening stretches into the speaker's present or even future.

Example 14.32 points up a fundamental difference between Lojban tenses and English tenses. An English past-tense sentence like “I went to the market” generally signifies that the going-to-the-market is entirely in the past; that is, that the event is complete at the time of speaking. Lojban pu has no such implication.

This property of a past tense is sometimes called “aorist”, in reference to a similar concept in the tense system of Classical Greek. All of the Lojban tenses have the same property, however:

Example 14.33:

le tricu ba crino
The tree [future] is-green.
The tree will be green.

does not imply (as the colloquial English translation does) that the tree is not green now. The vague interval throughout which the tree is, in fact, green may have already started.

This general principle does not mean that Lojban has no way of indicating that a tree will be green but is not yet green. Indeed, there are several ways of expressing that concept: See Section 14.9 (event contours) and Section 14.19 (logical connection between tenses).

Dimensionality: VIhA

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning vi'i VIhA on a line vi'a VIhA in an area vi'u VIhA through a volume vi'e VIhA throughout a space/time interval </tab>

The cmavo of ZEhA are sufficient to express time intervals. One fundamental difference between space and time, however, is that space is multi-dimensional. Sometimes we want to say not only that something moves over a small interval, but also perhaps that it moves in a line. Lojban allows for this. I can specify that a motion “in a small space” is more specifically “in a short line”, “in a small area”, or “through a small volume”.

What about the child walking on the ice in Example 14.23 through Example 14.25? Given the nature of ice, probably the area interpretation is most sensible. I can make this assumption explicit with the appropriate member of selma'o VIhA:

Example 14.34:

le verba ve'a vi'a cadzu le bisli
The child [medium space interval] [2-dimensional] walks-on the ice.
In a medium-sized area, the child walks on the ice.

Space intervals can contain either VEhA or VIhA or both, but if both, VEhA must come first, as Example 14.34 shows.

The reader may wish to raise a philosophical point here. (Readers who don't wish to, should skip this paragraph.) The ice may be two-dimensional, or more accurately its surface may be, but since the child is three-dimensional, her walking must also be. The subjective nature of Lojban tense comes to the rescue here: the action is essentially planar, and the third dimension of height is simply irrelevant to walking. Even walking on a mountain could be called vi'a, because relatively speaking the mountain is associated with an essentially two-dimensional surface. Motion which is not confined to such a surface (e.g., flying, or walking through a three-dimensional network of tunnels, or climbing among mountains rather than on a single mountain) would be properly described with vi'u. So the cognitive, rather than the physical, dimensionality controls the choice of VIhA cmavo.

VIhA has a member vi'e which indicates a 4-dimensional interval, one that involves both space and time. This allows the spatial tenses to invade, to some degree, the temporal tenses; it is possible to make statements about space-time considered as an Einsteinian whole. (There are presently no cmavo of FAhA assigned to “pastward” and “futureward” considered as space rather than time directions – they could be added, though, if Lojbanists find space-time expression useful.) If a temporal tense cmavo is used in the same tense construct with a vi'e interval, the resulting tense may be self-contradictory.

Movement in space: MOhI

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning mo'i MOhI movement flag </tab>

All the information carried by the tense constructs so far presented has been presumed to be static: the bridi is occurring somewhere or other in space and time, more or less remote from the speaker. Suppose the truth of the bridi itself depends on the result of a movement, or represents an action being done while the speaker is moving? This too can be represented by the tense system, using the cmavo mo'i (of selma'o MOhI) plus a spatial direction and optional distance; the direction now refers to a direction of motion rather than a static direction from the speaker.

Example 14.35:

le verba mo'i ri'u cadzu le bisli
The child [movement] [right] walks-on the ice.
The child walks toward my right on the ice.

This is quite different from:

Example 14.36:

le verba ri'u cadzu le bisli
The child [right] walks-on the ice.
To the right of me, the child walks on the ice.

In either case, however, the reference frame for defining “right” and “left” is the speaker's, not the child's. This can be changed thus:

Example 14.37:

le verba mo'i ri'u cadzu le bisli ma'i vo'a
The child [movement] [right] walks on the ice in-reference-frame the-x1-place.
The child walks toward her right on the ice.

Example 14.37 is analogous to Example 14.35. The cmavo ma'i belongs to selma'o BAI (explained in Section 13.5), and allows specifying a reference frame.

Both a regular and a mo'i-flagged spatial tense can be combined, with the mo'i construct coming last:

Example 14.38:

le verba zu'avu mo'i ri'uvi cadzu le bisli
The child [left] [long] [movement] [right] [short] walks-on the ice.
Far to the left of me, the child walks a short distance toward my right on the ice.

It is not grammatical to use multiple directions like

zu'a ca'u after mo'i, but complex movements can be expressed in a separate bridi.

Here is an example of a movement tense on a bridi not inherently involving movement:

Example 14.39:

mi mo'i ca'uvu citka le mi sanmi
I [movement] [front] [long] eat my meal.
While moving a long way forward, I eat my meal.

(Perhaps I am eating in an airplane.)

There is no parallel facility in Lojban at present for expressing movement in time – time travel – but one could be added easily if it ever becomes useful.

Interval properties: TAhE and roi

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning di'i TAhE regularly na'o TAhE typically ru'i TAhE continuously ta'e TAhE habitually

di'inai TAhE irregularly na'onai TAhE atypically ru'inai TAhE intermittently ta'enai TAhE contrary to habit

roi ROI “n” times roinai ROI other than “n” times

ze'e ZEhA whole time interval ve'e VEhA whole space interval </tab>

Consider Lojban bridi which express events taking place in time. Whether a very short interval (a point) or a long interval of time is involved, the event may not be spread consistently throughout that interval. Lojban can use the cmavo of selma'o TAhE to express the idea of continuous or non-continuous actions.

Example 14.40:

mi puzu ze'u velckule
I [past] [long distance] [long interval] am-a-school-attendee (pupil).
Long ago I attended school for a long time.

probably does not mean that I attended school continuously throughout the whole of that long-ago interval. Actually, I attended school every day, except for school holidays. More explicitly,

Example 14.41:

mi puzu ze'u di'i velckule
I [past] [long distance] [long interval] [regularly] am-a-pupil.
Long ago I regularly attended school for a long time.

The four TAhE cmavo are differentiated as follows: ru'i covers the entirety of the interval, di'i covers the parts of the interval which are systematically spaced subintervals; na'o covers part of the interval, but exactly which part is determined by context; ta'e covers part of the interval, selected with reference to the behavior of the actor (who often, but not always, appears in the x1 place of the bridi).

Using TAhE does not require being so specific. Either the time direction or the time interval or both may be omitted (in which case they are vague). For example:

Example 14.42:

mi ba ta'e klama le zarci
I [future] [habitually] go-to the market.
I will habitually go to the market.
I will make a habit of going to the market.

specifies the future, but the duration of the interval is indefinite. Similarly,

Example 14.43:

mi na'o klama le zarci
I [typically] go-to the market.
I typically go/went/will go to the market.

illustrates an interval property in isolation. There are no distance or direction cmavo, so the point of time is vague; likewise, there is no interval cmavo, so the length of the interval during which these goings-to-the-market take place is also vague. As always, context will determine these vague values.

“Intermittently” is the polar opposite notion to “continuously”, and is expressed not with its own cmavo, but by adding the negation suffix

-nai (which belongs to selma'o NAI) to ru'i. For example:
Example 14.44:

le verba ru'inai cadzu le bisli
The child [continuously-not] walks-on the ice.
The child intermittently walks on the ice.

As shown in the cmavo table above, all the cmavo of TAhE may be negated with

-nai; ru'inai and di'inai are probably the most useful.

An intermittent event can also be specified by counting the number of times during the interval that it takes place. The cmavo roi (which belongs to selma'o ROI) can be appended to a number to make a quantified tense. Quantified tenses are common in English, but not so commonly named: they are exemplified by the adverbs “never”, “once”, “twice”, “thrice”, ... “always”, and by the related phrases “many times”, “a few times”, “too many times”, and so on. All of these are handled in Lojban by a number plus -roi:

Example 14.45:

mi paroi klama le zarci
I [one time] go-to the market.
I go to the market once.
Example 14.46:

mi du'eroi klama le zarci
I [too-many times] go-to the market.
I go to the market too often.

With the quantified tense alone, we don't know whether the past, the present, or the future is intended, but of course the quantified tense need not stand alone:

Example 14.47:

mi pu reroi klama le zarci
I [past] [two times] go-to the market.
I went to the market twice.

The English is slightly over-specific here: it entails that both goings-to-the-market were in the past, which may or may not be true in the Lojban sentence, since the implied interval is vague. Therefore, the interval may start in the past but extend into the present or even the future.


-nai to roi is also permitted, and has the meaning “other than (the number specified)”:
Example 14.48:

le ratcu reroinai citka le cirla
The rat [twice-not] eats the cheese.
The rat eats the cheese other than twice.

This may mean that the rat eats the cheese fewer times, or more times, or not at all.

It is necessary to be careful with sentences like Example 14.45 and Example 14.47, where a quantified tense appears without an interval. What Example 14.47 really says is that during an interval of unspecified size, at least part of which was set in the past, the event of my going to the market happened twice. The example says nothing about what happened outside that vague time interval. This is often less than we mean. If we want to nail down that I went to the market once and only once, we can use the cmavo ze'e which represents the “whole time interval”: conceptually, an interval which stretches from time's beginning to its end:

Example 14.49:

mi ze'e paroi klama le zarci
I [whole interval] [once] go-to the market.

Since specifying no ZEhA leaves the interval vague, Example 14.47 might in appropriate context mean the same as Example 14.49 after all – but Example 14.49 allows us to be specific when specificity is necessary.

A PU cmavo following ze'e has a slightly different meaning from one that follows another ZEhA cmavo. The compound cmavo

ze'epu signifies the interval stretching from the infinite past to the reference point (wherever the imaginary journey has taken you);
ze'eba is the interval stretching from the reference point to the infinite future. The remaining form,
ze'eca, makes specific the “whole of time” interpretation just given. These compound forms make it possible to assert that something has never happened without asserting that it never will.
Example 14.50:

mi ze'epu noroi klama le zarci
I [whole interval] [past] [never] go-to the market.
I have never gone to the market.

says nothing about whether I might go in future.

The space equivalent of ze'e is ve'e, and it can be used in the same way with a quantified space tense: see Section 14.10 for an explanation of space interval modifiers.

Event contours: ZAhO and re'u

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning pu'o ZAhO inchoative ca'o ZAhO continuitive ba'o ZAhO perfective co'a ZAhO initiative co'u ZAhO cessitive mo'u ZAhO completitive za'o ZAhO superfective co'i ZAhO achievative de'a ZAhO pausative di'a ZAhO resumptive

re'u ROI ordinal tense </tab>

The cmavo of selma'o ZAhO express the Lojban version of what is traditionally called “aspect”. This is not a notion well expressed by English tenses, but many languages (including Chinese and Russian among Lojban's six source languages) consider it more important than the specification of mere position in time.

The “event contours” of selma'o ZAhO, with their bizarre keywords, represent the natural portions of an event considered as a process, an occurrence with an internal structure including a beginning, a middle, and an end. Since the keywords are scarcely self-explanatory, each ZAhO will be explained in detail here. Note that from the viewpoint of Lojban syntax, ZAhOs are interval modifiers like TAhEs or ROI compounds; if both are found in a single tense, the TAhE/ROI comes first and the ZAhO afterward. The imaginary journey described by other tense cmavo moves us to the portion of the event-as-process which the ZAhO specifies.

It is important to understand that ZAhO cmavo, unlike the other tense cmavo, specify characteristic portions of the event, and are seen from an essentially timeless perspective. The “beginning” of an event is the same whether the event is in the speaker's present, past, or future. It is especially important not to confuse the speaker-relative viewpoint of the PU tenses with the event-relative viewpoint of the ZAhO tenses.

The cmavo pu'o, ca'o, and ba'o (etymologically derived from the PU cmavo) refer to an event that has not yet begun, that is in progress, or that has ended, respectively:

Example 14.51:

mi pu'o damba
I [inchoative] fight.
I'm on the verge of fighting.
Example 14.52:

la stiv. ca'o bacru
Steve [continuitive] utters.
Steve continues to talk.
Example 14.53:

le verba ba'o cadzu le bisli
The child [perfective] walks-on the ice.
The child is finished walking on the ice.

As discussed in Section 14.5, the simple PU cmavo make no assumptions about whether the scope of a past, present, or future event extends into one of the other tenses as well. Example 14.51 through Example 14.53 illustrate that these ZAhO cmavo do make such assumptions possible: the event in 10.1 has not yet begun, definitively; likewise, the event in 10.3 is definitely over.

Note that in Example 14.51 and Example 14.53, pu'o and ba'o may appear to be reversed: pu'o, although etymologically connected with pu, is referring to a future event; whereas ba'o, connected with ba, is referring to a past event. This is the natural result of the event-centered view of ZAhO cmavo. The inchoative, or pu'o, part of an event, is in the “pastward” portion of that event, when seen from the perspective of the event itself. It is only by inference that we suppose that Example 14.51 refers to the speaker's future: in fact, no PU tense is given, so the inchoative part of the event need not be coincident with the speaker's present: pu'o is not necessarily, though in fact often is, the same as

ca pu'o.

The cmavo in Example 14.51 through Example 14.53 refer to spans of time. There are also two points of time that can be usefully associated with an event: the beginning, marked by co'a, and the end, marked by co'u. Specifically, co'a marks the boundary between the pu'o and ca'o parts of an event, and co'u marks the boundary between the ca'o and ba'o parts:

Example 14.54:

mi ba co'a citka le mi sanmi
I [future] [initiative] eat my meal.
I will begin to eat my meal.
Example 14.55:

mi pu co'u citka le mi sanmi
I [past] [cessitive] eat my meal.
I ceased eating my meal.

Compare Example 14.54 with:

Example 14.56:

mi ba di'i co'a bajra
I [future] [regularly] [initiative] run.
I will regularly begin to run.

which illustrates the combination of a TAhE with a ZAhO.

A process can have two end points, one reflecting the “natural end” (when the process is complete) and the other reflecting the “actual stopping point” (whether complete or not). Example 14.55 may be contrasted with:

Example 14.57:

mi pu mo'u citka le mi sanmi
I [past] [completitive] eat my meal.
I finished eating my meal.

In Example 14.57, the meal has reached its natural end; in Example 14.55, the meal has merely ceased, without necessarily reaching its natural end.

A process such as eating a meal does not necessarily proceed uninterrupted. If it is interrupted, there are two more relevant point events: the point just before the interruption, marked by de'a, and the point just after the interruption, marked by di'a. Some examples:

Example 14.58:

mi pu de'a citka le mi sanmi
I [past] [pausative] eat my meal.
I stopped eating my meal (with the intention of resuming).
Example 14.59:

mi ba di'a citka le mi sanmi
I [future] [resumptive] eat my meal.
I will resume eating my meal.

In addition, it is possible for a process to continue beyond its natural end. The span of time between the natural and the actual end points is represented by za'o:

Example 14.60:

le ctuca pu za'o ciksi le cmaci seldanfu le tadgri
The teacher [past] [superfective] explained the mathematics problem to the student-group.
The teacher kept on explaining the mathematics problem to the class too long.

That is, the teacher went on explaining after the class already understood the problem.

An entire event can be treated as a single moment using the cmavo co'i:

Example 14.61:

la djan. pu co'i catra la djim
John [past] [achievative] kills Jim.
John was at the point in time where he killed Jim.

Finally, since an activity is cyclical, an individual cycle can be referred to using a number followed by re'u, which is the other cmavo of selma'o ROI:

Example 14.62:

mi pare'u klama le zarci
I [first time] go-to the store.
I go to the store for the first time (within a vague interval).

Note the difference between:

Example 14.63:

mi pare'u paroi klama le zarci
I [first time] [one time] go-to the store.
For the first time, I go to the store once.


Example 14.64:

mi paroi pare'u klama le zarci
I [one time] [first time] go-to the store.
There is one occasion on which I go to the store for the first time.

Space interval modifiers: FEhE

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning fe'e FEhE space interval modifier flag </tab>

Like time intervals, space intervals can also be continuous, discontinuous, or repetitive. Rather than having a whole separate set of selma'o for space interval properties, we instead prefix the flag fe'e to the cmavo used for time interval properties. A space interval property would be placed just after the space interval size and/or dimensionality cmavo:

Example 14.65:

ko vi'i fe'e di'i sombo le gurni
You-imperative [1-dimensional] [space:] [regularly] sow the grain.
Sow the grain in a line and evenly!
Example 14.66:

mi fe'e ciroi tervecnu lo selsalta
I [space:] [three places] buy those-which-are salad-ingredients.
I buy salad ingredients in three locations.
Example 14.67:

ze'e roroi ve'e fe'e roroi ku li re su'i re du li vo
[whole time] [all times] [whole space] [space:] [all places] The-number 2 + 2 = the-number 4.
Always and everywhere, two plus two is four.

As shown in Example 14.67, when a tense comes first in a bridi, rather than in its normal position before the selbri (in this case du), it is emphasized.

The fe'e marker can also be used for the same purpose before members of ZAhO. (The cmavo be'a belongs to selma'o FAhA; it is the space direction meaning “north of”.)

Example 14.68:

tu ve'abe'a fe'e co'a rokci
That-yonder [medium space interval - north] [space] [initiative] is-a-rock.
That is the beginning of a rock extending to my north.
That is the south face of a rock.

Here the notion of a “beginning point” represented by the cmavo co'a is transferred from “beginning in time” to “beginning in space” under the influence of the fe'e flag. Space is not inherently oriented, unlike time, which flows from past to future: therefore, some indication of orientation is necessary, and the ve'abe'a provides an orientation in which the south face is the “beginning” and the north face is the “end”, since the rock extends from south (near me) to north (away from me).

Many natural languages represent time by a space-based metaphor: in English, what is past is said to be “behind us”. In other languages, the metaphor is reversed. Here, Lojban is representing space (or space interval modifiers) by a time-based metaphor: the choice of a FAhA cmavo following a VEhA cmavo indicates which direction is mapped onto the future. (The choice of future rather than past is arbitrary, but convenient for English-speakers.)

If both a TAhE (or ROI) and a ZAhO are present as space interval modifiers, the fe'e flag must be prefixed to each.

Tenses as sumti tcita

So far, we have seen tenses only just before the selbri, or (equivalently in meaning) floating about the bridi with ku. There is another major use for tenses in Lojban: as sumti tcita, or argument tags. A tense may be used to add spatial or temporal information to a bridi as, in effect, an additional place:

Example 14.69:

mi klama le zarci ca le nu do klama le zdani
I go-to the market [present] the event-of you go-to the house.
I go to the market when you go to the house.

Here ca does not appear before the selbri, nor with ku; instead, it governs the following sumti, the

le nu construct. What Example 14.69 asserts is that the action of the main bridi is happening at the same time as the event mentioned by that sumti. So ca, which means “now” when used with a selbri, means “simultaneously-with” when used with a sumti. Consider another example:

Example 14.70:

mi klama le zarci pu le nu do pu klama le zdani
I go-to the market [past] the event-of you [past] go-to the house.

The second pu is simply the past tense marker for the event of your going to the house, and says that this event is in the speaker's past. How are we to understand the first pu, the sumti tcita?

All of our imaginary journeys so far have started at the speaker's location in space and time. Now we are specifying an imaginary journey that starts at a different location, namely at the event of your going to the house. Example 14.70 then says that my going to the market is in the past, relative not to the speaker's present moment, but instead relative to the moment when you went to the house. Example 14.70 can therefore be translated:

I had gone to the market before you went to the house.

(Other translations are possible, depending on the ever-present context.) Spatial direction and distance sumti tcita are exactly analogous:

Example 14.71:

le ratcu cu citka le cirla vi le panka
The rat eats the cheese [short distance] the park.
The rat eats the cheese near the park.
Example 14.72:

le ratcu cu citka le cirla vi le vu panka
The rat eats the cheese [short distance] the [long distance] park
The rat eats the cheese near the faraway park.
Example 14.73:

le ratcu cu citka le cirla vu le vi panka
The rat eats the cheese [long distance] the [short distance] park
The rat eats the cheese far away from the nearby park.

The event contours of selma'o ZAhO (and their space equivalents, prefixed with fe'e) are also useful as sumti tcita. The interpretation of ZAhO tcita differs from that of FAhA, VA, PU, and ZI tcita, however. The event described in the sumti is viewed as a process, and the action of the main bridi occurs at the phase of the process which the ZAhO specifies, or at least some part of that phase. The action of the main bridi itself is seen as a point event, so that there is no issue about which phase of the main bridi is intended. For example:

Example 14.74:

mi morsi ba'o le nu mi jmive
I am-dead [perfective] the event-of I live.
I die in the aftermath of my living.

Here the (point-)event of my being dead is the portion of my living-process which occurs after the process is complete. Contrast Example 14.74 with:

Example 14.75:

mi morsi ba le nu mi jmive
I am-dead [future] the event-of I live.

As explained in Section 14.5, Example 14.75 does not exclude the possibility that I died before I ceased to live!

Likewise, we might say:

Example 14.76:

mi klama le zarci pu'o le nu mi citka
I go-to the store [inchoative] the event-of I eat

which indicates that before my eating begins, I go to the store, whereas

Example 14.77:

mi klama le zarci ba'o le nu mi citka
I go-to the store [perfective] the event-of I eat

would indicate that I go to the store after I am finished eating.

Here is an example which mixes temporal ZAhO (as a tense) and spatial ZAhO (as a sumti tcita):

Example 14.78:

le bloti pu za'o xelklama fe'e ba'o le lalxu
The boat [past] [superfective] is-a-transport-mechanism [space] [perfective] the lake.
The boat sailed for too long and beyond the lake.

Probably it sailed up onto the dock. One point of clarification: although xelklama appears to mean simply “is-a-mode-of-transport”, it does not – the bridi of Example 14.78 has four omitted arguments, and thus has the (physical) journey which goes on too long as part of its meaning.

The remaining tense cmavo, which have to do with interval size, dimension, and continuousness (or lack thereof) are interpreted to let the sumti specify the particular interval over which the main bridi operates:

Example 14.79:

mi klama le zarci reroi le ca djedi
I go-to the market [twice] the [present] day.
I go/went/will go to the market twice today.

Be careful not to confuse a tense used as a sumti tcita with a tense used within a seltcita sumti:

Example 14.80:

loi snime cu carvi ze'u le ca dunra
Some-of-the-mass-of snow rains [long time interval] the [present] winter.
Snow falls during this winter.

claims that the interval specified by “this winter” is long, as events of snowfall go, whereas

Example 14.81:

loi snime cu carvi ca le ze'u dunra
Some-of-the-mass-of snow rains [present] the [long time] winter.
Snow falls in the long winter.

claims that during some part of the winter, which is long as winters go, snow falls.

Sticky and multiple tenses: KI

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ki KI sticky tense set/reset </tab>

So far we have only considered tenses in isolated bridi. Lojban provides several ways for a tense to continue in effect over more than a single bridi. This property is known as “stickiness”: the tense gets “stuck” and remains in effect until explicitly “unstuck”. In the metaphor of the imaginary journey, the place and time set by a sticky tense may be thought of as a campsite or way-station: it provides a permanent origin with respect to which other tenses are understood. Later imaginary journeys start from that point rather than from the speaker.

To make a tense sticky, suffix ki to it:

Example 14.82:

mi puki klama le zarci .i le nanmu cu batci le gerku
I [past] [sticky] go-to the market. The man bites the dog.
I went to the market. The man bit the dog.

Here the use of

puki rather than just pu ensures that the tense will affect the next sentence as well. Otherwise, since the second sentence is tenseless, there would be no way of determining its tense; the event of the second sentence might happen before, after, or simultaneously with that of the first sentence.

(The last statement does not apply when the two sentences form part of a narrative. See Section 14.13 for an explanation of “story time”, which employs a different set of conventions.)

What if the second sentence has a tense anyway?

Example 14.83:

mi puki klama le zarci .i le nanmu pu batci le gerku
I [past] [sticky] go-to the market. The man [past] bites the dog.

Here the second pu does not replace the sticky tense, but adds to it, in the sense that the starting point of its imaginary journey is taken to be the previously set sticky time. So the translation of Example 14.83 is:

Example 14.84:

I went to the market. The man had earlier bitten the dog.

and it is equivalent in meaning (when considered in isolation from any other sentences) to:

Example 14.85:

mi pu klama le zarci .i le nanmu pupu batci le gerku
I [past] go-to the market. The man [past] [past] bites the dog.

The point has not been discussed so far, but it is perfectly grammatical to have more than one tense construct in a sentence:

Example 14.86:

puku mi ba klama le zarci
[past] I [future] go-to the market.
Earlier, I was going to go to the market.

Here there are two tenses in the same bridi, the first floating free and specified by

puku, the second in the usual place and specified by ba. They are considered cumulative in the same way as the two tenses in separate sentences of Example 14.85. Example 14.86 is therefore equivalent in meaning, except for emphasis, to:
Example 14.87:

mi puba klama le zarci
I [past] [future] go-to the market.
I was going to go to the market.

Compare Example 14.88 and Example 14.89, which have a different meaning from Example 14.86 and Example 14.87:

Example 14.88:

mi ba klama le zarci puku
I [future] go-to the market [past].
I will have gone to the market earlier.
Example 14.89:

mi bapu klama le zarci
I [future] [past] go-to the market.
I will have gone to the market.

So when multiple tense constructs in a single bridi are involved, order counts – the tenses cannot be shifted around as freely as if there were only one tense to worry about.

But why bother to allow multiple tense constructs at all? They specify separate portions of the imaginary journey, and can be useful in order to make part of a tense sticky. Consider Example 14.90, which adds a second bridi and a ki to Example 14.86:

Example 14.90:

pukiku mi ba klama le zarci .i le nanmu cu batci le gerku
[past] [sticky] I [future] go-to the market. The man bites the dog.

What is the implied tense of the second sentence? Not puba, but only pu, since only pu was made sticky with ki. So the translation is:

I was going to go to the market. The man bit the dog.

Lojban has several ways of embedding a bridi within another bridi: descriptions, abstractors, relative clauses. (Technically, descriptions contain selbri rather than bridi.) Any of the selbri of these subordinate bridi may have tenses attached. These tenses are interpreted relative to the tense of the main bridi:

Example 14.91:

mi pu klama le ba'o zarci
I [past] go-to the [perfective] market
I went to the former market.

The significance of the ba'o in Example 14.91 is that the speaker's destination is described as being “in the aftermath of being a market”; that is, it is a market no longer. In particular, the time at which it was no longer a market is in the speaker's past, because the ba'o is interpreted relative to the pu tense of the main bridi.

Here is an example involving an abstraction bridi:

Example 14.92:

mi ca jinvi le du'u mi ba morsi
I now opine the fact-that I will-be dead.
I now believe that I will be dead.

Here the event of being dead is said to be in the future with respect to the opinion, which is in the present.

ki may also be used as a tense by itself. This cancels all stickiness and returns the bridi and all following bridi to the speaker's location in both space and time.

In complex descriptions, multiple tenses may be saved and then used by adding a subscript to ki. A time made sticky with

kixipa (ki-sub-1) can be returned to by specifying
kixipa as a tense by itself. In the case of written expression, the writer's here-and-now is often different from the reader's, and a pair of subscripted ki tenses could be used to distinguish the two.

Story time

Making strict use of the conventions explained in Section 14.12 would be intolerably awkward when a story is being told. The time at which a story is told by the narrator is usually unimportant to the story. What matters is the flow of time within the story itself. The term “story” in this section refers to any series of statements related in more-or-less time-sequential order, not just a fictional one.

Lojban speakers use a different set of conventions, commonly called “story time”, for inferring tense within a story. It is presumed that the event described by each sentence takes place some time more or less after the previous ones. Therefore, tenseless sentences are implicitly tensed as “what happens next”. In particular, any sticky time setting is advanced by each sentence.

The following mini-story illustrates the important features of story time. A sentence-by-sentence explication follows:

Example 14.93:

puzuki ku ne'iki le kevna le ninmu goi ko'a zutse le rokci
[past] [long] [sticky] [,] [inside] [sticky] the cave, the woman defined-as she-1 sat-on the rock
Long ago, in a cave, a woman sat on a rock.
Example 14.94:

.i ko'a citka loi kanba rectu
She-1 [tenseless] eat some-of-the-mass-of goat flesh.
She was eating goat's meat.
Example 14.95:

.i ko'a pu jukpa ri le mudyfagri
She [past] cook the-last-mentioned by-method the wood-fire.
She had cooked the meat over a wood fire.
Example 14.96:

.i lei rectu cu zanglare
The-mass-of flesh is-(favorable)-warm.
The meat was pleasantly warm.
Example 14.97:

.i le labno goi ko'e bazaki nenri klama le kevna
The wolf defined-as it-2 [future] [medium] [sticky] within-came to-the cave.
A while later, a wolf came into the cave.
Example 14.98:

.i ko'e lebna lei rectu ko'a
It-2 [tenseless] takes the-mass-of flesh from-her-1.
It took the meat from her.
Example 14.99:

.i ko'e bartu klama
It-2 out ran
It ran out.

Example 14.93 sets both the time (long ago) and the place (in a cave) using ki, just like the sentence sequences in Section 14.12. No further space cmavo are used in the rest of the story, so the place is assumed to remain unchanged. The English translation of Example 14.93 is marked for past tense also, as the conventions of English storytelling require: consequently, all other English translation sentences are also in the past tense. (We don't notice how strange this is; even stories about the future are written in past tense!) This conventional use of past tense is not used in Lojban narratives.Example 14.94 is tenseless. Outside story time, it would be assumed that its event happens simultaneously with that of Example 14.93, since a sticky tense is in effect; the rules of story time, however, imply that the event occurs afterwards, and that the story time has advanced (changing the sticky time set in Example 14.93).Example 14.95 has an explicit tense. This is taken relative to the latest setting of the sticky time; therefore, the event of Example 14.95 happens before that of Example 14.94. It cannot be determined if Example 14.95 happens before or after Example 14.93.Example 14.96 is again tenseless. Story time was not changed by the flashback in Example 14.95, so Example 14.96 happens after Example 14.94.Example 14.97 specifies the future (relative to Example 14.96) and makes it sticky. So all further events happen after Example 14.97.Example 14.98 and Example 14.99 are again tenseless, and so happen after Example 14.97. (Story time is changed.)

So the overall order is Example 14.93 - Example 14.95 - Example 14.94 - Example 14.96 - (medium interval) - Example 14.97 - Example 14.98 - Example 14.99. It is also possible that Example 14.95 happens before Example 14.93.

If no sticky time (or space) is set initially, the story is set at an unspecified time (or space): the effect is like that of choosing an arbitrary reference point and making it sticky. This style is common in stories that are jokes. The same convention may be used if the context specifies the sticky time sufficiently.

Tenses in subordinate bridi

English has a set of rules, formally known as “sequence of tense rules”, for determining what tense should be used in a subordinate clause, depending on the tense used in the main sentence. Here are some examples:

Example 14.100:

John says that George is going to the market.

Example 14.101:

John says that George went to the market.

Example 14.102:

John said that George went to the market.

Example 14.103:

John said that George had gone to the market.

In Example 14.100 and Example 14.101, the tense of the main sentence is the present: “says”. If George goes when John speaks, we get the present tense “is going” ( “goes” would be unidiomatic); if George goes before John speaks, we get the past tense “went”. But if the tense of the main sentence is the past, with “said”, then the tense required in the subordinate clause is different. If George goes when John speaks, we get the past tense “went”; if George goes before John speaks, we get the past-perfect tense “had gone”.

The rule of English, therefore, is that both the tense of the main sentence and the tense of the subordinate clause are understood relative to the speaker of the main sentence (not John, but the person who speaks Example 14.100 through Example 14.103).

Lojban, like Russian and Esperanto, uses a different convention. A tense in a subordinate bridi is understood to be relative to the tense already set in the main bridi. Thus Example 14.100 through Example 14.103 can be expressed in Lojban respectively thus:

Example 14.104:

la djan. ca cusku le se du'u la djordj. ca klama le zarci
John [present] says the statement-that George [present] goes-to the market.
Example 14.105:

la djan. ca cusku le se du'u la djordj. pu klama le zarci
John [present] says the statement-that George [past] goes-to the market.
Example 14.106:

la djan. pu cusku le se du'u la djordj. ca klama le zarci
John [past] says the statement-that George [present] goes-to the market.
Example 14.107:

la djan. pu cusku le se du'u la djordj. pu klama le zarci
John [past] says the statement-that George [past] goes-to the market.

Probably the most counterintuitive of the Lojban examples is Example 14.106. The ca looks quite odd, as if George were going to the market right now, rather than back when John spoke. But this ca is really a ca with respect to a reference point specified by the outer pu. This behavior is the same as the additive behavior of multiple tenses in the same bridi, as explained in Section 14.12.

There is a special cmavo nau (of selma'o CUhE) which can be used to override these rules and get to the speaker's current reference point. (Yes, it sounds like English “now”.) It is not grammatical to combine nau with any other cmavo in a tense, except by way of a logical or non-logical connection (see Section 14.19). Here is a convoluted sentence with several nested bridi which uses nau at the lowest level:

Example 14.108:

la djan. pu cusku le se du'u la .alis pu cusku le se du'u la djordj. pu cusku le se du'u la maris. nau klama le zarci
John [past] says the statement-that Alice [past] says the statement-that George [past] says the statement that Mary [now] goes-to the market.
John said that Alice had said that George had earlier said that Mary is now going to the market.

The use of nau does not affect sticky tenses.

Tense relations between sentences

The sumti tcita method, explained in Section 14.11, of asserting a tense relationship between two events suffers from asymmetry. Specifically,

Example 14.109:

le verba cu cadzu le bisli zu'a le nu le nanmu cu batci le gerku
The child walks-on the ice [left] the event-of the man bites the dog.
The child walks on the ice to the left of where the man bites the dog.

which specifies an imaginary journey leftward from the man biting the dog to the child walking on the ice, claims only that the child walks on the ice. By the nature of

le nu, the man's biting the dog is merely referred to without being claimed. If it seems desirable to claim both, each event can be expressed as a main sentence bridi, with a special form of i connecting them:
Example 14.110:

le nanmu cu batci le gerku .izu'abo le verba cu cadzu le bisli
The man bites the dog. [Left] the child walks-on the ice.
The man bites the dog. To the left, the child walks on the ice.
.izu'abo is a compound cmavo: the i separates the sentences and the zu'a is the tense. The bo is required to prevent the zu'a from gobbling up the following sumti, namely
le verba.

Note that the bridi in Example 14.110 appear in the reverse order from their appearance in Example 14.109. With

.izu'abo (and all other afterthought tense connectives) the sentence specifying the origin of the journey comes first. This is a natural order for sentences, but requires some care when converting between this form and the sumti tcita form.Example 14.110 means the same thing as:
Example 14.111:

le nanmu cu batci le gerku .i zu'a la'edi'u le verba cu cadzu le bisli
The man bites the dog. [Left] the-referent-of-the-last-sentence the child walks-on the ice.
The man bites the dog. Left of what I just mentioned, the child walks on the ice.

If the bo is omitted in Example 14.110, the meaning changes:

Example 14.112:

le nanmu cu batci le gerku .i zu'a le verba cu cadzu le bisli
The man bites the dog. [Left] the child [something] walks-on the ice.
The man bites the dog. To the left of the child, something walks on the ice.

Here the first place of the second sentence is unspecified, because zu'a has absorbed the sumti

le verba.

Do not confuse either Example 14.110 or Example 14.112 with the following:

Example 14.113:

le nanmu cu batci le gerku .i zu'aku le verba cu cadzu le bisli
The man bites the dog. [Left] the child walks-on the ice.
The man bites the dog. Left of me, the child walks on the ice.

In Example 14.113, the origin point is the speaker, as is usual with zu'aku. Example 14.110 makes the origin point of the tense the event described by the first sentence.

Two sentences may also be connected in forethought by a tense relationship. Just like afterthought tense connection, forethought tense connection claims both sentences, and in addition claims that the time or space relationship specified by the tense holds between the events the two sentences describe.

The origin sentence is placed first, preceded by a tense plus gi. Another gi is used to separate the sentences:

Example 14.114:

pugi mi klama le zarci gi mi klama le zdani
[past] I go-to the market [,] I go-to the house.
Before I go to the market, I go to the house.

A parallel construction can be used to express a tense relationship between sumti:

Example 14.115:

mi klama pugi le zarci gi le zdani
I go-to [past] the market [,] the house.

Because English does not have any direct way of expressing a tense-like relationship between nouns, Example 14.115 cannot be expressed in English without paraphrasing it either into Example 14.114 or else into “I go to the house before the market”, which is ambiguous – is the market going?

Finally, a third forethought construction expresses a tense relationship between bridi-tails rather than whole bridi. (The construct known as a “bridi-tail” is explained fully in Section 16.21; roughly speaking, it is a selbri, possibly with following sumti.) Example 14.116 is equivalent in meaning to Example 14.114 and Example 14.115:

Example 14.116:

mi pugi klama le zarci gi klama le zdani
I [past] go-to the market [,] go-to the house.
I, before going to the market, go to the house.

In both Example 14.115 and Example 14.116, the underlying sentences

mi klama le zarci and
mi klama le zdani are not claimed; only the relationship in time between them is claimed.

Both the forethought and the afterthought forms are appropriate with PU, ZI, FAhA, VA, and ZAhO tenses. In all cases, the equivalent forms are (where X and Y stand for sentences, and TENSE for a tense cmavo):

X TENSE le nu Y
afterthought coordinate:
Y .i+TENSE+bo X
forethought coordinate:
TENSE+gi X gi Y

Tensed logical connectives

The Lojban tense system interacts with the Lojban logical connective system. That system is a separate topic, explained in Chapter ELG-ERROR in Template:Lch and touched on only in summary here. By the rules of the logical connective system, Example 14.117 through 17.3 are equivalent in meaning:

Example 14.117:

la teris. satre le mlatu .ije la teris. satre le ractu
Terry strokes the cat. And Terry strokes the rabbit.
Example 14.118:

la teris. satre le mlatu gi'e satre le ractu
Terry strokes the cat and strokes the rabbit.
Example 14.119:

la teris. satre le mlatu .e le ractu
Terry strokes the cat and the rabbit.

Suppose we wish to add a tense relationship to the logical connective “and”? To say that Terry strokes the cat and later strokes the rabbit, we can combine a logical connective with a tense connective by placing the logical connective first, then the tense, and then the cmavo bo, thus:

Example 14.120:

la teris. satre le mlatu .ijebabo la teris. satre le ractu
Terry strokes the cat. And then Terry strokes the rabbit.
Example 14.121:

la teris. satre le mlatu gi'ebabo satre le ractu
Terry strokes the cat, and then strokes the rabbit.
Example 14.122:

la teris. satre le mlatu .ebabo le ractu
Terry strokes the cat and then the rabbit.

Example 14.120 through 17.6 are equivalent in meaning. They are also analogous to Example 14.117 through Example 14.119 respectively. The bo is required for the same reason as in Example 14.110: to prevent the ba from functioning as a sumti tcita for the following sumti (or, in Example 14.121, from being attached to the following selbri).

In addition to the bo construction of Example 14.120 through Example 14.122, there is also a form of tensed logical connective with keke'e ( tu'etu'u for sentences). The logical connective system makes Example 14.123 through Example 14.125 equivalent in meaning:

Example 14.123:

mi bevri le dakli .ije tu'e mi bevri le gerku .ija mi bevri le mlatu tu'u
I carry the sack. And (I carry the dog. And/or I carry the cat).
I carry the sack. And I carry the dog, or I carry the cat, or I carry both.
Example 14.124:

mi bevri le dakli gi'eke bevri le gerku gi'a bevri le mlatu
I carry the sack and (carry the dog and/or carry the cat).
I carry the sack, and also carry the dog or carry the cat or carry both.
Example 14.125:

mi bevri le dakli .eke le gerku .a le mlatu
I carry the sack and (the dog or the cat).
I carry the sack and also the dog or the cat or both.

Note the uniformity of the Lojban, as contrasted with the variety of ways in which the English provides for the correct grouping. In all cases, the meaning is that I carry the sack in any case, and either the cat or the dog or both.

To express that I carry the sack first (earlier in time), and then the dog or the cat or both simultaneously, I can insert tenses to form Example 14.126 through Example 14.128:

Example 14.126:

mi bevri le dakli .ije ba tu'e mi bevri le gerku .ijacabo mi bevri le mlatu tu'u
I carry the sack. And [future] (I carry the dog. And/or [present] I carry the cat.)
I carry the sack. And then I will carry the dog or I will carry the cat or I will carry both at once.
Example 14.127:

mi bevri le dakli gi'ebake bevri le gerku gi'acabo bevri le mlatu
I carry the sack and [future] (carry the dog and/or [present] carry the cat).
I carry the sack and then will carry the dog or carry the cat or carry both at once.
Example 14.128:

mi bevri le dakli .ebake le gerku .acabo le mlatu
I carry the sack and [future] (the cat and/or [present] the dog).
I carry the sack, and then the cat or the dog or both at once.

Example 14.126 through Example 14.128 are equivalent in meaning to each other, and correspond to the tenseless Example 14.123 through Example 14.125 respectively.

Tense negation

Any bridi which involves tenses of selma'o PU, FAhA, or ZAhO can be contradicted by a

-nai suffixed to the tense cmavo. Some examples:
Example 14.129:

mi punai klama le zarci
I [past] [not] go-to the market.
I didn't go to the market.

As a contradictory negation, Example 14.129 implies that the bridi as a whole is false without saying anything about what is true. When the negated tense is a sumti tcita,

-nai negation indicates that the stated relationship does not hold:
Example 14.130:

mi klama le zarci canai le nu do klama le zdani
I go-to the market [present] [not] the event-of you go-to the house.
It is not true that I went to the market at the same time that you went to the house.
Example 14.131:

le nanmu batci le gerku ne'inai le kumfa
The man bites the dog [within] [not] the room.
The man didn't bite the dog inside the room.
Example 14.132:

mi morsi ca'onai le nu mi jmive
I am-dead [continuitive - negated] the event-of I live.
It is false that I am dead during my life.

It is also possible to perform scalar negation of whole tense constructs by placing a member of NAhE before them. Unlike contradictory negation, scalar negation asserts a truth: that the bridi is true with some tense other than that specified. The following examples are scalar negation analogues of Example 14.129 to Example 14.131:

Example 14.133:

mi na'e pu klama le zarci
I [non-] [past] go-to the market.
I go to the market other than in the past.
Example 14.134:

le nanmu batci le gerku to'e ne'i le kumfa
The man bites the dog [opposite-of] [within] the room.
The man bites the dog outside the room.
Example 14.135:

mi klama le zarci na'e ca le nu do klama le zdani
I go-to the market [non-] [present] the event-of you go-to the house.
I went to the market at a time other than the time at which you went to the house.
Example 14.136:

mi morsi na'e ca'o le nu mi jmive
I am-dead [non-] [continuitive] the event-of I live.
I am dead other than during my life.


-nai contradictory negation, scalar negation of tenses is not limited to PU and FAhA:
Example 14.137:

le verba na'e ri'u cadzu le bisli
The child [non-] [right] walks-on the ice
The child walks on the ice other than to my right.

The use of

-nai on cmavo of TAhE and ROI has already been discussed in Section 14.8; this use is also a scalar negation.

Actuality, potentiality, capability: CAhA

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ca'a CAhA actually is ka'e CAhA is innately capable of nu'o CAhA can but has not pu'i CAhA can and has </tab>

Lojban bridi without tense markers may not necessarily refer to actual events: they may also refer to capabilities or potential events. For example:

Example 14.138:

ro datka cu flulimna
All ducks are-float-swimmers.
All ducks swim by floating.

is a Lojban truth, even though the colloquial English translation is false or at best ambiguous. This is because the tenseless Lojban bridi doesn't necessarily claim that every duck is swimming or floating now or even at a specific time or place. Even if we add a tense marker to Example 14.138,

Example 14.139:

ro datka ca flulimna
All ducks [present] are-float-swimmers.
All ducks are now swimming by floating.

the resulting Example 14.139 might still be considered a truth, even though the colloquial English seems even more likely to be false. All ducks have the potential of swimming even if they are not exercising that potential at present. To get the full flavor of “All ducks are now swimming”, we must append a marker from selma'o CAhA to the tense, and say:

Example 14.140:

ro datka ca ca'a flulimna
All ducks [present] [actual] are-float-swimmers.
All ducks are now actually swimming by floating.

A CAhA cmavo is always placed after any other tense cmavo, whether for time or for space. However, a CAhA cmavo comes before ki, so that a CAhA condition can be made sticky.Example 14.140 is false in both Lojban and English, since it claims that the swimming is an actual, present fact, true of every duck that exists, whereas in fact there is at least one duck that is not swimming now.

Furthermore, some ducks are dead (and therefore sink); some ducks have just hatched (and do not know how to swim yet), and some ducks have been eaten by predators (and have ceased to exist as separate objects at all). Nevertheless, all these ducks have the innate capability of swimming – it is part of the nature of duckhood. The cmavo ka'e expresses this notion of innate capability:

Example 14.141:

ro datka ka'e flulimna
All ducks [capable] are-float-swimmers.
All ducks are innately capable of swimming.

Under some epistemologies, innate capability can be extended in order to apply the innate properties of a mass to which certain individuals belong to the individuals themselves, even if those individuals are themselves not capable of fulfilling the claim of the bridi. For example:

Example 14.142:

la djan. ka'e viska
John [capable] sees.
John is innately capable of seeing.
John can see.

might be true about a human being named John, even though he has been blind since birth, because the ability to see is innately built into his nature as a human being. It is theoretically possible that conditions might occur that would enable John to see (a great medical discovery, for example). On the other hand,

Example 14.143:

le cukta ka'e viska
The book [capable] sees.
The book can see.

is not true in most epistemologies, since the ability to see is not part of the innate nature of a book.

Consider once again the newly hatched ducks mentioned earlier. They have the potential of swimming, but have not yet demonstrated that potential. This may be expressed using nu'o, the cmavo of CAhA for undemonstrated potential:

Example 14.144:

ro cifydatka nu'o flulimna
All infant-ducks [can but has not] are-float-swimmers.
All infant ducks have an undemonstrated potential for swimming by floating.
Baby ducks can swim but haven't yet.

Contrariwise, if Frank is not blind from birth, then pu'i is appropriate:

Example 14.145:

la frank. pu'i viska
Frank [can and has] sees.
Frank has demonstrated a potential for seeing.
Frank can see and has seen.

Note that the glosses given at the beginning of this section for ca'a, nu'o, and pu'i incorporate ca into their meaning, and are really correct for

ca ca'a,
ca nu'o, and
ca pu'i. However, the CAhA cmavo are perfectly meaningful with other tenses than the present:
Example 14.146:

mi pu ca'a klama le zarci
I [past] [actual] go-to the store.
I actually went to the store.
Example 14.147:

la frank. ba nu'o klama le zdani
Frank [future] [can but has not] goes-to the store.
Frank could have, but will not have, gone to the store
(at some understood moment in the future).

As always in Lojban tenses, a missing CAhA can have an indeterminate meaning, or the context can be enough to disambiguate it. Saying

Example 14.148:

ta jelca
That burns/is-burning/might-burn/will-burn.

with no CAhA specified can translate the two very different English sentences “That is on fire” and “That is inflammable.” The first demands immediate action (usually), whereas the second merely demands caution. The two cases can be disambiguated with:

Example 14.149:

ta ca ca'a jelca
That [present] [actual] burns.
That is on fire.


Example 14.150:

ta ka'e jelca
That [capable] burns.
That is capable of burning.
That is inflammable.

When no indication is given, as in the simple observative

Example 14.151:

It burns!

the prudent Lojbanist will assume the meaning “Fire!”

Logical and non-logical connections between tenses

Like many things in Lojban, tenses may be logically connected; logical connection is explained in more detail in Chapter ELG-ERROR in Template:Lch. Some of the terminology in this section will be clear only if you already understand logical connectives.

The appropriate logical connectives belong to selma'o JA. A logical connective between tenses can always be expanded to one between sentences:

Example 14.152:

mi pu je ba klama le zarci
I [past] and [future] go-to the market.
I went and will go to the market.

means the same as:

Example 14.153:

mi pu klama le zarci .ije mi ba klama le zarci
I [past] go-to the market. And I [future] go-to the market.
I went to the market, and I will go to the market.

Tense connection and tense negation are combined in:

Example 14.154:

mi punai je canai je ba klama le zarci
I [past] [not] and [present] [not] and [future] go-to the market.
I haven't yet gone to the market, but I will in future.

Example 14.154 is far more specific than

Example 14.155:

mi ba klama le zarci
I [future] go-to the market.

which only says that I will go, without claiming anything about my past or present. ba does not imply

punai or
canai; to compel that interpretation, either a logical connection or a ZAhO is needed.

Tense negation can often be removed in favor of negation in the logical connective itself. The following examples are equivalent in meaning:

Example 14.156:

mi mo'izu'anai je mo'iri'u cadzu
I [motion] [left-not] and [motion] [right] walk.
I walk not leftward but rightward.
Example 14.157:

mi mo'izu'a naje mo'iri'u cadzu
I [motion] [left] not-and [motion] [right] walk.
I walk not leftward but rightward.

There are no forethought logical connections between tenses allowed by the grammar, to keep tenses simpler. Nor is there any way to override simple left-grouping of the connectives, the Lojban default.

The non-logical connectives of selma'o JOI, BIhI, and GAhO are also permitted between tenses. One application is to specify intervals not by size, but by their end-points ( bi'o belongs to selma'o BIhI, and connects the end-points of an ordered interval, like English “from ... to”):

Example 14.158:

mi puza bi'o bazu vasxu
I [past] [medium] from ... to [future] [long] breathe.
I breathe from a medium time ago till a long time to come.

(It is to be hoped that I have a long life ahead of me.)

One additional use of non-logical connectives within tenses is discussed in Section 14.20. Other uses will probably be identified in future.


Another application of non-logical tense connection is to talk about sub-events of events. Consider a six-shooter: a gun which can fire six bullets in succession before reloading. If I fire off the entire magazine twice, I can express the fact in Lojban thus:

Example 14.159:

mi reroi pi'u xaroi cecla le seldanti
I [twice] [cross-product] [six times] shoot the projectile-launcher.
On two occasions, I fire the gun six times.

It would be confusing, though grammatical, to run the reroi and the

xaroi directly together. However, the non-logical connective pi'u expresses a Cartesian product (also known as a cross product) of two sets. In this case, there is a set of two firings each of which is represented by a set of six shots, for twelve shots in all (hence the name “product”: the product of 2 and 6 is 12). Its use specifies very precisely what occurs.

In fact, you can specify strings of interval properties and event contours within a single tense without the use of a logical or non-logical connective cmavo. This allows tenses of the type:

Example 14.160:

la djordj. ca'o co'a ciska
George [continuitive] [initiative] writes.
George continues to start to write.
Example 14.161:

mi reroi ca'o xaroi darxi le damri
I [twice] [continuitive] [six times] hit the drum.
On two occasions, I continue to beat the drum six times.

Conversion of sumti tcita: JAI

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning jai JAI tense conversion fai FA indefinite place </tab>

Conversion is the regular Lojban process of moving around the places of a place structure. The cmavo of selma'o SE serve this purpose, exchanging the first place with one of the others:

Example 14.162:

mi cu klama le zarci
I go-to the market.
Example 14.163:

le zarci cu se klama mi
The market is-gone-to by-me.

It is also possible to bring a place that is specified by a sumti tcita (for the purposes of this chapter, a tense sumti tcita) to the front, by using jai plus the tense as the grammatical equivalent of SE:

Example 14.164:

le ratcu cu citka le cirla vi le panka
The rat eats the cheese [short distance] the park.
The rat eats the cheese in the park.
Example 14.165:

le panka cu jai vi citka le cirla fai le ratcu
The park is-the-place-of eating the cheese by-the rat.
The park is where the rat eats the cheese.

In Example 14.165, the construction JAI+tense converts the location sumti into the first place. The previous first place has nowhere to go, since the location sumti is not a numbered place; however, it can be inserted back into the bridi with fai, the indefinite member of selma'o FA.

(The other members of FA are used to mark the first, second, etc. places of a bridi explicitly:

Example 14.166:

fa mi cu klama fe le zarci

means the same as

Example 14.167:

fe le zarci cu klama fa mi

as well as the simple

Example 14.168:

mi cu klama le zarci

in which the place structure is determined by position.)

Like SE conversion, JAI+tense conversion is especially useful in descriptions with LE selma'o:

Example 14.169:

mi viska le jai vi citka be le cirla
I saw the place-of eating the cheese.

Here the eater of the cheese is elided, so no fai appears.

Of course, temporal tenses are also usable with JAI:

Example 14.170:

mi djuno fi le jai ca morsi be fai la djan.

I know about the [present] is-dead of-the-one-called “John”.

I know the time of John's death.
I know when John died.

Tenses versus modals

Grammatically, every use of tenses seen so far is exactly paralleled by some use of modals as explained in Chapter 13. Modals and tenses alike can be followed by sumti, can appear before the selbri, can be used in pure and mixed connections, can participate in JAI conversions. The parallelism is perfect. However, there is a deep difference in the semantics of tense constructs and modal constructs, grounded in historical differences between the two forms. Originally, modals and tenses were utterly different things in earlier versions of Loglan; only in Lojban have they become grammatically interchangeable. And even now, differences in semantics continue to be maintained.

The core distinction is that whereas the modal bridi

Example 14.171:

mi nelci do mu'i le nu do nelci mi
I like you with-motivation the event-of you like me.
I like you because you like me.

places the

le nu sumti in the x1 place of the gismu mukti (which underlies the modal mu'i), namely the motivating event, the tensed bridi
Example 14.172:

mi nelci do ba le nu do nelci mi
I like you after the event-of you like me.
I like you after you like me.

places the

le nu sumti in the x2 place of the gismu balvi (which underlies the tense ba), namely the point of reference for the future tense. Paraphrases of Example 14.171 and Example 14.172, employing the brivla mukti and balvi explicitly, would be:
Example 14.173:

le nu do nelci mi cu mukti le nu mi nelci do
The event-of you like me motivates the event-of I like you.
Your liking me is the motive for my liking you.


Example 14.174:

le nu mi nelci do cu balvi le nu do nelci mi
The event-of I like you is after the event of you like me.
My liking you follows (in time) your liking me.

(Note that the paraphrase is not perfect due to the difference in what is claimed; Example 14.173 and Example 14.174 claim only the causal and temporal relationships between the events, not the existence of the events themselves.)

As a result, the afterthought sentence-connective forms of Example 14.171 and Example 14.172 are, respectively:

Example 14.175:

mi nelci do .imu'ibo do nelci mi
I like you. [That is] Because you like me.
Example 14.176:

do nelci mi .ibabo mi nelci do
You like me. Afterward, I like you.

In Example 14.175, the order of the two bridi

mi nelci do and
do nelci mi is the same as in Example 14.171. In Example 14.176, however, the order is reversed: the origin point
do nelci mi physically appears before the future-time event
mi nelci do. In both cases, the bridi characterizing the event in the x2 place appears before the bridi characterizing the event in the x1 place of mukti or balvi.

In forethought connections, however, the asymmetry between modals and tenses is not found. The forethought equivalents of Example 14.175 and Example 14.176 are

Example 14.177:

mu'igi do nelci mi gi mi nelci do
Because you like me, I like you.


Example 14.178:

bagi do nelci mi gi mi nelci do
After you like me, I like you.


The following modal sentence schemata (where X and Y represent sentences) all have the same meaning:

X .i BAI bo Y
BAI gi Y gi X
X BAI le nu Y

whereas the following tensed sentence schemata also have the same meaning:

X .i TENSE bo Y
TENSE gi X gi Y
Y TENSE le nu X

neglecting the question of what is claimed. In the modal sentence schemata, the modal tag is always followed by Y, the sentence representing the event in the x1 place of the gismu that underlies the BAI. In the tensed sentences, no such simple rule exists.

Tense questions: cu'e

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning cu'e CUhE tense question </tab>

There are two main ways to ask questions about tense. The main English tense question words are “When?” and “Where?”. These may be paraphrased respectively as “At what time?” and “At what place?” In these forms, their Lojban equivalents simply involve a tense plus ma, the Lojban sumti question:

Example 14.179:

do klama le zdani ca ma
You go-to the house [present] [what sumti?].
You go to the house at what time?
When do you go to the house?
Example 14.180:

le verba vi ma pu cadzu le bisli
The child [short space] [what sumti?] [past] walks-on the ice.
The child at/near what place walked on the ice?
Where did the child walk on the ice?

There is also a non-specific tense and modal question, cu'e, belonging to selma'o CUhE. This can be used wherever a tense or modal construct can be used.

Example 14.181:

le nanmu cu'e batci le gerku
The man [what tense?] bites the dog.
When/Where/How does the man bite the dog?

Possible answers to Example 14.181 might be:

Example 14.182:

[medium space].
Some ways from here.
Example 14.183:

[past] [long time].
A long time ago.
Example 14.184:

vi le lunra
[short space] The moon.
On the moon.
Example 14.185:

He hasn't yet done so.

or even the modal reply (from selma'o BAI; See Section 13.5):

Example 14.186:

seka'a le briju
With-destination the office.

The only way to combine cu'e with other tense cmavo is through logical connection, which makes a question that pre-specifies some information:

Example 14.187:

do puzi je cu'e sombo le gurni
You [past] [short] and [when?] sow the grain?
You sowed the grain a little while ago; when else do you sow it?

Additionally, the logical connective itself can be replaced by a question word:

Example 14.188:

la .artr. pu je'i ba nolraitru
Arthur [past] [which?] [future] is-a-king
Was Arthur a king or will he be?

Answers to Example 14.188 would be logical connectives such as je, meaning “both”,

naje meaning “the latter”, or jenai meaning “the former”.

Explicit magnitudes

It is a limitation of the VA and ZI system of specifying magnitudes that they can only prescribe vague magnitudes: small, medium, or large. In order to express both an origin point and an exact distance, the Lojban construction called a “termset” is employed. (Termsets are explained further in Section 16.23 and Section 17.6.) It is grammatical for a termset to be placed after a tense or modal tag rather than a sumti, which allows both the origin of the imaginary journey and its distance to be specified. Here is an example:

Example 14.189:

la frank. sanli zu'a nu'i la djordj. la'u lo mitre be li mu [nu'u]
Frank stands [left] [start termset] George [quantity] a thing-measuring-in-meters the-number 5 [end termset].
Frank is standing five meters to the left of George.

Here the termset extends from the nu'i to the implicit nu'u at the end of the sentence, and includes the terms

la djordj., which is the unmarked origin point, and the tagged sumti
lo mitre be li mu, which the cmavo la'u (of selma'o BAI, and meaning “with quantity”; See Section 13.5) marks as a quantity. Both terms are governed by the tag zu'a

It is not necessary to have both an origin point and an explicit magnitude: a termset may have only a single term in it. A less precise version of Example 14.189 is:

Example 14.190:

la frank. sanli zu'a nu'i la'u lo mitre be li mu
Frank stands [left] [termset] [quantity] a thing-measuring-in-meters the-number 5.
Frank stands five meters to the left.

Finally (an exercise for the much-tried reader)

Example 14.191:

.a'o do pu seju ba roroi ca'o fe'e su'oroi jimpe fi le lojbo temci selsku ciste

Summary of tense selma'o

<tab class=wikitable> cmavo selma'o subclass meaning PU temporal direction

pu = past, ca = present, ba = future

ZI temporal distance

zi = short, za = medium, zu = long

ZEhA temporal interval

ze'i = short, ze'a = medium, ze'u = long, ze'e = infinite

ROI objective quantified tense flag

noroi = never, paroi = once, ..., roroi = always, etc.
pare'u = the first time, rere'u = the second time, etc.

TAhE subjective quantified tense

di'i = regularly, na'o = typically, ru'i = continuously, ta'e = habitually

ZAhO event contours

see Section 10

FAhA spatial direction

see Section 28

VA spatial distance

vi = short, va = medium, vu = long

VEhA spatial interval

ve'i = short, ve'a = medium, ve'u = long, ve'e = infinite

VIhA spatial dimensionality

vi'i = line, vi'a = plane, vi'u = space, vi'e = space-time

FEhE spatial interval modifier flag

fe'enoroi = nowhere, fe'eroroi = everywhere, fe'eba'o = beyond, etc.

MOhI spatial movement flag

mo'i = motion; see Section 28

KI set or reset sticky tense

tense+“ki” = set, “ki” alone = reset

CUhE tense question, reference point

cu'e = asks for a tense or aspect, nau = use speaker’s reference point

JAI tense conversion

jaica = the time of, jaivi = the place of, etc.


List of spatial directions and direction-like relations

The following list of FAhA cmavo gives rough English glosses for the cmavo, first when used without mo'i to express a direction, and then when used with mo'i to express movement in the direction. When possible, the gismu from which the cmavo is derived is also listed. <tab class=wikitable> cmavo selma'o subclass meaning cmavo gismu without mo'i with mo'i ----- ----- ------------ --------- ca'u crane in front (of) forward ti'a trixe behind backward zu'a zunle on the left (of) leftward ri'u pritu on the right (of) rightward ga'u gapru above upward(ly) ni'a cnita below downward(ly) ne'i nenri within into ru'u sruri surrounding orbiting pa'o pagre transfixing passing through ne'a next to ' moving while next to te'e bordering ' moving along the border (of) re'o adjacent (to) ' along fa'a farna towards arriving at to'o away from ' departing from zo'i inward (from) ' approaching ze'o outward (from) ' receding from zo'a tangential (to) ' passing (by) 'bu'u ' coincident (with) moving to coincide with be'a berti north (of) northward(ly) ne'u snanu south (of) southward(ly) du'a stuna east (of) eastward(ly) vu'a west (of) ' westward(ly) </tab>

Special note on fa'a, to'o, zo'i, and ze'o: zo'i and ze'o refer to direction towards or away from the speaker's location, or whatever the origin is. fa'a and to'o refer to direction towards or away from some other point.


The syntax of abstraction

The purpose of the feature of Lojban known as “abstraction” is to provide a means for taking whole bridi and packaging them up, as it were, into simple selbri. Syntactically, abstractions are very simple and uniform; semantically, they are rich and complex, with few features in common between one variety of abstraction and another. We will begin by discussing syntax without regard to semantics; as a result, the notion of abstraction may seem unmotivated at first. Bear with this difficulty until Section 16.1.

An abstraction selbri is formed by taking a full bridi and preceding it by any cmavo of selma'o NU. There are twelve such cmavo; they are known as “abstractors”. The bridi is closed by the elidable terminator kei, of selma'o KEI. Thus, to change the bridi

Example 16.1:

mi klama le zarci
I go-to the store

into an abstraction using nu, one of the members of selma'o NU, we change it into

Example 16.2:

nu mi klama le zarci [kei]
an-event-of my going-to the store

The bridi may be a simple selbri, or it may have associated sumti, as here. It is important to beware of eliding kei improperly, as many of the common uses of abstraction selbri involve following them with words that would appear to be part of the abstraction if kei had been elided.

(Technically, kei is never necessary, because the elidable terminator vau that closes every bridi can substitute for it; however, kei is specific to abstractions, and using it is almost always clearer.)

The grammatical uses of an abstraction selbri are exactly the same as those of a simple brivla. In particular, abstraction selbri may be used as observatives, as in Example 16.2, or used in tanru:

Example 16.3:

la djan. cu nu sonci kei djica
John is-an-(event-of being-a-soldier) type-of desirer.
John wants to be a soldier.

Abstraction selbri may also be used in descriptions, preceded by le (or any other member of selma'o LE):

Example 16.4:

la djan. cu djica le nu sonci [kei]
John desires the event-of being-a-soldier.

We will most often use descriptions containing abstraction either at the end of a bridi, or just before the main selbri with its cu; in either of these circumstances, kei can normally be elided.

The place structure of an abstraction selbri depends on the particular abstractor, and will be explained individually in the following sections.

Note: In glosses of bridi within abstractions, the grammatical form used in the English changes. Thus, in the gloss of Example 16.2 we see “my going-to the store” rather than “I go-to the store”; likewise, in the glosses of Example 16.3 and Example 16.4 we see “being-a-soldier” rather than “is-a-soldier”. This procedure reflects the desire for more understandable glosses, and does not indicate any change in the Lojban form. A bridi is a bridi, and undergoes no change when it is used as part of an abstraction selbri.

Event abstraction

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning nu NU event abstractor </tab>

The examples in Section made use of nu as the abstractor, and it is certainly the most common abstractor in Lojban text. Its purpose is to capture the event or state of the bridi considered as a whole. Do not confuse the le description built on a nu abstraction with ordinary descriptions based on le alone. The following sumti are quite distinct:

Example 16.5:

le klama
the comer, that which comes
Example 16.6:

le se klama
the destination
Example 16.7:

le te klama
the origin
Example 16.8:

le ve klama
the route
Example 16.9:

le xe klama
the means of transportation
Example 16.10:

le nu klama
the event of someone coming to somewhere from somewhere by some route using some means

Example 16.5 through Example 16.9 are descriptions that isolate the five individual sumti places of the selbri klama. Example 16.10 describes something associated with the bridi as a whole: the event of it.

In Lojban, the term “event” is divorced from its ordinary English sense of something that happens over a short period of time. The description:

Example 16.11:

le nu mi vasxu
the event-of my breathing

is an event which lasts for the whole of my life (under normal circumstances). On the other hand,

Example 16.12:

le nu la djan. cinba la djein.
the event-of John kissing Jane

is relatively brief by comparison (again, under normal circumstances).

We can see from Example 16.10 through Example 16.12 that ellipsis of sumti is valid in the bridi of abstraction selbri, just as in the main bridi of a sentence. Any sumti may be ellipsized if the listener will be able to figure out from context what the proper value of it is, or else to recognize that the proper value is unimportant. It is extremely common for nu abstractions in descriptions to have the x1 place ellipsized:

Example 16.13:

mi nelci le nu limna
I like the event-of swimming.
I like swimming.

is elliptical, and most probably means:

Example 16.14:

mi nelci le nu mi limna
I like the event-of I swim.

In the proper context, of course, Example 16.13 could refer to the event of somebody else swimming. Its English equivalent, “I like swimming”, can't be interpreted as “I like Frank's swimming”; this is a fundamental distinction between English and Lojban. In Lojban, an omitted sumti can mean whatever the context indicates that it should mean.

Note that the lack of an explicit NU cmavo in a sumti can sometimes hide an implicit abstraction. In the context of Example 16.14, the appearance of

le se nelci ( “that which is liked”) is in effect an abstraction:
Example 16.15:

le se nelci cu cafne
The liked-thing is-frequent.
The thing which I like happens often.

which in this context means

My swimming happens often.

Event descriptions with

le nu are commonly used to fill the “under conditions...” places, among others, of gismu and lujvo place structures:
Example 16.16:

la lojban. cu frili mi le nu mi tadni [kei]
Lojban is-easy for-me under-conditions-the event-of I study
Lojban is easy for me when I study.

(The “when” of the English would also be appropriate for a construction involving a Lojban tense, but the Lojban sentence says more than that the studying is concurrent with the ease.)

The place structure of a nu abstraction selbri is simply:

x1 is an event of (the bridi)

Types of event abstractions

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning mu'e NU point-event abstractor pu'u NU process abstractor zu'o NU activity abstractor za'i NU state abstractor </tab>

Event abstractions with nu suffice to express all kinds of events, whether long, short, unique, repetitive, or whatever. Lojban also has more finely discriminating machinery for talking about events, however. There are four other abstractors of selma'o NU for talking about four specific types of events, or four ways of looking at the same event.

An event considered as a point in time is called a “point-event”, or sometimes an “achievement”. (This latter word should be divorced, in this context, from all connotations of success or triumph.) A point-event can be extended in duration, but it is still a point-event if it is thought of as unitary, having no internal structure. The abstractor mu'e means “point-event-of”:

Example 16.17:

le mu'e la djan. catra la djim. cu zekri
The point-event-of (John kills Jim) is-a-crime.
John's killing Jim (considered as a point in time) is a crime.

An event considered as extended in time, and structured with a beginning, a middle containing one or more stages, and an end, is called a “process”. The abstractor pu'u means “process-of”:

Example 16.18:

ca'o le pu'u le latmo balje'a cu porpi kei so'i je'atru cu selcatra
[continuitive] the process-of( the Latin great-state breaking-up ) many state-rulers were-killed
During the fall of the Roman Empire, many Emperors were killed.

An event considered as extended in time and cyclic or repetitive is called an “activity”. The abstractor zu'o means “activity-of”:

Example 16.19:

mi tatpi ri'a le zu'o mi plipe
I am-tired because-of the activity-of (I jump).
I am tired because I jump.

An event considered as something that is either happening or not happening, with sharp boundaries, is called a “state”. The abstractor za'i means “state-of”:

Example 16.20:

le za'i mi jmive cu ckape do
The state-of (I am-alive) is-dangerous-to you.
My being alive is dangerous to you.

The abstractors in Example 16.17 through Example 16.20 could all have been replaced by nu, with some loss of precision. Note that Lojban allows every sort of event to be viewed in any of these four ways:

  • the “state of running” begins when the runner starts and ends when the runner stops;
  • the “activity of running” consists of the cycle “lift leg, step forward, drop leg, lift other leg...” (each such cycle is a process, but the activity consists in the repetition of the cycle);
  • the “process of running” puts emphasis on the initial sprint, the steady speed, and the final slowdown;
  • the “achievement of running” is most alien to English, but sees the event of running as a single indivisible thing, like “Pheidippides' run from Marathon to Athens” (the original marathon).

Further information on types of events can be found in Section 16.11.

The four event type abstractors have the following place structures:

mu'e :x1 is a point event of (the bridi) pu'u: x1 is a process of (the bridi) with stages x2 za'i: x1 is a continuous state of (the bridi) being true zu'o: x1 is an activity of (the bridi) consisting of repeated actions x2

Property abstractions

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ka NU property abstractor ce'u KOhA abstraction focus </tab> The things described by

le nu descriptions (or, to put it another way, the things of which nu selbri may correctly be predicated) are only moderately “abstract”. They are still closely tied to happenings in space and time. Properties, however, are much more ethereal. What is “the property of being blue”, or “the property of being a go-er”? They are what logicians call “intensions”. If John has a heart, then “the property of having a heart” is an abstract object which, when applied to John, is true. In fact,
Example 16.21:

la djan. cu se risna zo'e
John has-as-heart something-unspecified.
John has a heart.

has the same truth conditions as

Example 16.22:

la djan. cu ckaji le ka se risna [zo'e] [kei]
John has-the-property the property-of having-as-heart something.
John has the property of having a heart.

(The English word “have” frequently appears in any discussion of Lojban properties: things are said to “have” properties, but this is not the same sense of “have” as in “I have money”, which is possession.)

Property descriptions, like event descriptions, are often wanted to fill places in brivla place structures:

Example 16.23:

do cnino mi le ka xunre [kei]
You are-new to-me in-the-quality-of-the property-of being-red.
You are new to me in redness.

(The English suffix “-ness” often signals a property abstraction, as does the suffix “-ity”.)

We can also move the property description to the x1 place of Example 16.23, producing:

Example 16.24:

le ka do xunre [kei] cu cnino mi
The property-of your being-red is-new to me.
Your redness is new to me.

It would be suitable to use Example 16.23 and Example 16.24 to someone who has returned from the beach with a sunburn.

There are several different properties that can be extracted from a bridi, depending on which place of the bridi is “understood” as being specified externally. Thus:

Example 16.25:

ka mi prami [zo'e] [kei]
a-property-of me loving something-unspecified

is quite different from

Example 16.26:

ka [zo'e] prami mi [kei]
a-property-of something-unspecified loving me

In particular, sentences like Example 16.27 and Example 16.28 are quite different in meaning:

Example 16.27:

la djan. cu zmadu la djordj. le ka mi prami
John exceeds George in-the property-of (I love X)
I love John more than I love George.
Example 16.28:

la djan. cu zmadu la djordj. le ka prami mi
John exceeds George in the property of (X loves me).
John loves me more than George loves me.

The “X” used in the glosses of Example 16.27 through Example 16.28 as a place-holder cannot be represented only by ellipsis in Lojban, because ellipsis means that there must be a specific value that can fill the ellipsis, as mentioned in Section 16.1. Instead, the cmavo ce'u of selma'o KOhA is employed when an explicit sumti is wanted. (The form “X” will be used in literal translations.)

Therefore, an explicit equivalent of Example 16.27, with no ellipsis, is:

Example 16.29:

la djan. cu zmadu la djordj. le ka mi prami ce'u
John exceeds George in-the property-of (I love X).

and of Example 16.28 is:

Example 16.30:

la djan. cu zmadu la djordj. le ka ce'u prami mi
John exceeds George in-the property-of (X loves me).

This convention allows disambiguation of cases like:

Example 16.31:

le ka [zo'e] dunda le xirma [zo'e] [kei]
the property-of giving the horse


Example 16.32:

le ka ce'u dunda le xirma [zo'e] [kei]
the property-of (X is-a-giver of-the horse to someone-unspecified)
the property of being a giver of the horse

which is the most natural interpretation of Example 16.31, versus

Example 16.33:

le ka [zo'e] dunda le xirma ce'u [kei]
the property-of (someone-unspecified is-a-giver of-the horse to X)
the property of being one to whom the horse is given

which is also a possible interpretation.

It is also possible to have more than one ce'u in a ka abstraction, which transforms it from a property abstraction into a relationship abstraction. Relationship abstractions “package up” a complex relationship for future use; such an abstraction can be translated back into a selbri by placing it in the x2 place of the selbri bridi, whose place structure is: bridi :x1 is a predicate relationship with relation x2 (abstraction) among arguments (sequence/set) x3

The place structure of ka abstraction selbri is simply: ka :x1 is a property of (the bridi)

Amount abstractions

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning ni NU amount abstraction </tab>

Amount abstractions are far more limited than event or property abstractions. They really make sense only if the selbri of the abstracted bridi is subject to measurement of some sort. Thus we can speak of:

Example 16.34:

le ni le pixra cu blanu [kei]
the amount-of (the picture being-blue)
the amount of blueness in the picture

because “blueness” could be measured with a colorimeter or a similar device. However,

Example 16.35:

le ni la djein. cu mamta [kei]
the amount-of (Jane being-a-mother)
the amount of Jane's mother-ness (?)
the amount of mother-ness in Jane (?)

makes very little sense in either Lojban or English. We simply do not have any sort of measurement scale for being a mother.

Semantically, a sumti with

le ni is a number; however, it cannot be treated grammatically as a quantifier in Lojban unless prefixed by the mathematical cmavo mo'e:
Example 16.36:

li pa vu'u mo'e le ni le pixra cu blanu [kei]
the-number 1 minus the-operand the amount-of (the picture being-blue)
1 - B, where B = blueness of the picture

Mathematical Lojban is beyond the scope of this chapter, and is explained more fully in Chapter ELG-ERROR in Template:Lch.

There are contexts where either property or amount abstractions make sense, and in such constructions, amount abstractions can make use of ce'u just like property abstractors. Thus,

Example 16.37:

le pixra cu cenba le ka ce'u blanu [kei]
The picture varies in-the property-of (X is blue).
The picture varies in being blue.
The picture varies in blueness.

is not the same as

Example 16.38:

le pixra cu cenba le ni ce'u blanu [kei]
The picture varies in-the amount-of (X is blue).
The picture varies in how blue it is.
The picture varies in blueness.

Example 16.37 conveys that the blueness comes and goes, whereas Example 16.38 conveys that its quantity changes over time.

Whenever we talk of measurement of an amount, there is some sort of scale, and so the place structure of ni abstraction selbri is: ni :x1 is the amount of (the bridi) on scale x2

Note: the best way to express the x2 places of abstract sumti is to use something like le ni ... kei be. See Example 16.62 for the use of this construction.

Truth-value abstraction: jei

The “blueness of the picture” discussed in Section 16.4 refers to the measurable amount of blue pigment (or other source of blueness), not to the degree of truth of the claim that blueness is present. That abstraction is expressed in Lojban using jei, which is closely related semantically to ni. In the simplest cases,

le jei produces not a number but a truth value:
Example 16.39:

le jei li re su'i re du li vo [kei]
the truth-value-of the-number 2 + 2 = the-number 4
the truth of 2 + 2 being 4

is equivalent to “truth”, and

Example 16.40:

le jei li re su'i re du li mu [kei]
the truth-value-of the-number 2 + 2 = the-number 5
the truth of 2 + 2 being 5

is equivalent to “falsehood”.

However, not everything in life (or even in Lojban) is simply true or false. There are shades of gray even in truth value, and jei is Lojban's mechanism for indicating the shade of grey intended:

Example 16.41:

mi ba jdice le jei la djordj. cu zekri gasnu [kei]
I [future] decide the truth-value of (George being-a-(crime doer)).
I will decide whether George is a criminal.

Example 16.41 does not imply that George is, or is not, definitely a criminal. Depending on the legal system I am using, I may make some intermediate decision. As a result, jei requires an x2 place analogous to that of ni: jei :x1 is the truth value of (the bridi) under epistemology x2

Abstractions using jei are the mechanism for fuzzy logic in Lojban; the jei abstraction refers to a number between 0 and 1 inclusive (as distinct from ni abstractions, which are often on open-ended scales). The detailed conventions for using jei in fuzzy-logic contexts have not yet been established.

Predication/sentence abstraction

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning du'u NU predication abstraction </tab>

There are some selbri which demand an entire predication as a sumti; they make claims about some predication considered as a whole. Logicians call these the “propositional attitudes”, and they include (in English) things like knowing, believing, learning, seeing, hearing, and the like. Consider the English sentence:

Example 16.42:

I know that Frank is a fool.

How's that in Lojban? Let us try:

Example 16.43:

mi djuno le nu la frank. cu bebna [kei]
I know the event of Frank being a fool.

Not quite right. Events are actually or potentially physical, and can't be contained inside one's mind, except for events of thinking, feeling, and the like; Example 16.43 comes close to claiming that Frank's being-a-fool is purely a mental activity on the part of the speaker. (In fact, Example 16.43 is an instance of improperly marked “sumti raising”, a concept discussed further in Section 16.9).

Try again:

Example 16.44:

mi djuno le jei la frank. cu bebna [kei]
I know the truth-value of Frank being a fool.

Closer. Example 16.44 says that I know whether or not Frank is a fool, but doesn't say that he is one, as Example 16.42 does. To catch that nuance, we must say:

Example 16.45:

mi djuno le du'u la frank. cu bebna [kei]
I know the predication that Frank is a fool.

Now we have it. Note that the implied assertion “Frank is a fool” is not a property of le du'u abstraction, but of djuno; we can only know what is in fact true. (As a result, djuno like jei has a place for epistemology, which specifies how we know.) Example 16.46 has no such implied assertion:

Example 16.46:

mi kucli le du'u la frank. cu bebna [kei]
I am curious about whether Frank is a fool.

and here du'u could probably be replaced by jei without much change in meaning:

Example 16.47:

mi kucli le jei la frank. cu bebna [kei]
I am curious about how true it is that Frank is a fool.

As a matter of convenience rather than logical necessity, du'u has been given an x2 place, which is a sentence (piece of language) expressing the bridi: du'u :x1 is the predication (the bridi), expressed in sentence x2


le se du'u ... is very useful in filling places of selbri which refer to speaking, writing, or other linguistic behavior regarding bridi:
Example 16.48:

la djan. cusku le se du'u la djordj. klama le zarci [kei]
John expresses the sentence-expressing-that George goes-to the store
John says that George goes to the store.

Example 16.48 differs from

Example 16.49:

la djan cusku lu la djordj. klama le zarci li'u
John expresses, quote, George goes to the store, unquote.
John says “George goes to the store”.

because Example 16.49 claims that John actually said the quoted words, whereas Example 16.48 claims only that he said some words or other which were to the same purpose.

le se du'u is much the same as
lu'e le du'u, a symbol for the predication, but
se du'u can be used as a selbri, whereas lu'e is ungrammatical in a selbri. (See Section 8.9 for a discussion of lu'e.)

Indirect questions

The following cmavo is discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning kau UI indirect question marker </tab>

There is an alternative type of sentence involving du'u and a selbri expressing a propositional attitude. In addition to sentences like

Example 16.50:

I know that John went to the store.

we can also say things like

Example 16.51:

I know who went to the store.

This form is called an “indirect question” in English because the embedded English sentence is a question: “Who went to the store?” A person who says Example 16.51 is claiming to know the answer to this question. Indirect questions can occur with many other English verbs as well: I can wonder, or doubt, or see, or hear, as well as know who went to the store.

To express indirect questions in Lojban, we use a le du'u abstraction, but rather than using a question word like “who” ( ma in Lojban), we use any word that will fit grammatically and mark it with the suffix particle kau. This cmavo belongs to selma'o UI, so grammatically it can appear anywhere. The simplest Lojban translation of Example 16.51 is therefore:

Example 16.52:

mi djuno le du'u makau pu klama le zarci
I know the predication-of X [indirect question] [past] going to the store.

In Example 16.52, we have chosen to use ma as the word marked by kau. In fact, any other sumti would have done as well: zo'e or da or even

la djan.. Using
la djan. would suggest that it was John who I knew had gone to the store, however:
Example 16.53:

mi djuno le du'u la djan. kau pu klama le zarci
I know the predication-of/fact-that John [indirect question] [past] going to the store.
I know who went to the store, namely John.
I know that it was John who went to the store.

Using one of the indefinite pro-sumti such as ma, zo'e, or da does not suggest any particular value.

Why does Lojban require the kau marker, rather than using ma as English and Chinese and many other languages do? Because ma always signals a direct question, and so

Example 16.54:

mi djuno le du'u ma pu klama le zarci
I know the predication-of [what sumti?] [past] goes-to the store


Example 16.55:

Who is it that I know goes to the store?

It is actually not necessary to use

le du'u and kau at all if the indirect question involves a sumti; there is generally a paraphrase of the type:
Example 16.56:

mi djuno fi le pu klama be le zarci
I know about the [past] goer to-the store.
I know something about the one who went to the store (namely, his identity).

because the x3 place of djuno is the subject of knowledge, as opposed to the fact that is known. But when the questioned point is not a sumti, but (say) a logical connection, then there is no good alternative to kau:

Example 16.57:

mi ba zgana le du'u la djan. jikau la djordj. cu zvati le panka
I [future] observe the predication-of/fact-that John [connective indirect question] George is-at the park.
I will see whether John or George (or both) is at the park.

In addition, Example 16.56 is only a loose paraphrase of Example 16.52, because it is left to the listener's insight to realize that what is known about the goer-to-the-store is his identity rather than some other of his attributes.

Minor abstraction types

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning li'i NU experience abstractor si'o NU concept abstractor su'u NU general abstractor </tab>

There are three more abstractors in Lojban, all of them little used so far. The abstractor li'i expresses experience:

Example 16.58:

mi morji le li'i mi verba
I remember the experience-of (my being-a-child)

The abstractor si'o expresses a mental image, a concept, an idea:

Example 16.59:

mi nelci le si'o la lojban. cu mulno
I enjoy the concept-of Lojban being-complete.

Finally, the abstractor su'u is a vague abstractor, whose meaning must be grasped from context:

Example 16.60:

ko zgana le su'u le ci smacu cu bajra
you [imperative] observe the abstract-nature-of the three mice running
See how the three mice run!

All three of these abstractors have an x2 place. An experience requires an experiencer, so the place structure of li'i is: li'i :x1 is the experience of (the bridi) as experienced by x2

Similarly, an idea requires a mind to hold it, so the place structure of si'o is: si'o :x1 is the idea/concept of (the bridi) in the mind of x2

Finally, there needs to be some way of specifying just what sort of abstraction su'u is representing, so its place structure is: su'u :x1 is an abstract nature of (the bridi) of type x2

The x2 place of su'u allows it to serve as a substitute for any of the other abstractors, or as a template for creating new ones. For example,

Example 16.61:

le nu mi klama
the event-of my going

can be paraphrased as

Example 16.62:

le su'u mi klama kei be lo fasnu
the abstract-nature-of (my going) of-type an event

and there is a book whose title might be rendered in Lojban as:

Example 16.63:

le su'u la .iecuas. kuctai selcatra kei be lo sa'ordzifa'a ke nalmatma'e sutyterjvi
the abstract-nature-of (Jesus is-an-intersect-shape type-of-killed-one) of-type a slope-low-direction type-of non-motor-vehicle speed-competition
The Crucifixion of Jesus Considered As A Downhill Bicycle Race

Note the importance of using kei after su'u when the x2 of su'u (or any other abstractor) is being specified; otherwise, the be lo ends up inside the abstraction bridi.

Lojban sumti raising

The following cmavo are discussed in this section: <tab class=wikitable> cmavo selma'o subclass meaning tu'a LAhE an abstraction involving jai JAI abstraction conversion </tab>

It is sometimes inconvenient, in a situation where an abstract description is logically required, to express the abstraction. In English we can say:

Example 16.64:

I try to open the door.

which in Lojban is:

Example 16.65:

mi troci le nu [mi] gasnu le nu le vorme cu karbi'o
I try the event-of (I am-agent-in the event-of (the door open-becomes)).

which has an abstract description within an abstract description, quite a complex structure. In English (but not in all other languages), we may also say:

Example 16.66:

I try the door.

where it is understood that what I try is actually not the door itself, but the act of opening it. The same simplification can be done in Lojban, but it must be marked explicitly using a cmavo. The relevant cmavo is tu'a, which belongs to selma'o LAhE. The Lojban equivalent of Example 16.66 is:

Example 16.67:

mi troci tu'a le vorme
I try some-action-to-do-with the door.

The term “sumti-raising”, as in the title of this section, signifies that a sumti which logically belongs within an abstraction (or even within an abstraction which is itself inside an intermediate abstraction) is “raised” to the main bridi level. This transformation from Example 16.65 to Example 16.67 loses information: nothing except convention tells us what the abstraction was.

Using tu'a is a kind of laziness: it makes speaking easier at the possible expense of clarity for the listener. The speaker must be prepared for the listener to respond something like:

Example 16.68:

tu'a le vorme lu'u ki'a
something-to-do-with the door [terminator] [confusion!]

which indicates that

tu'a le vorme cannot be understood. (The terminator for tu'a is lu'u, and is used in Example 16.68 to make clear just what is being questioned: the sumti-raising, rather than the word vorme as such.) An example of a confusing raised sumti might be:
Example 16.69:

tu'a la djan. cu cafne
something-to-do-with John frequently-occurs

This must mean that something which John does, or which happens to John, occurs frequently: but without more context there is no way to figure out what. Note that without the tu'a, Example 16.69 would mean that John considered as an event frequently occurs – in other words, that John has some sort of on-and-off existence! Normally we do not think of people as events in English, but the x1 place of cafne is an event, and if something that does not seem to be an event is put there, the Lojbanic listener will attempt to construe it as one. (Of course, this analysis assumes that djan. is the name of a person, and not the name of some event.)

Logically, a counterpart of some sort is needed to tu'a which transposes an abstract sumti into a concrete one. This is achieved at the selbri level by the cmavo jai (of selma'o JAI). This cmavo has more than one function, discussed in Section 13.11 and Section 14.21; for the purposes of this chapter, it operates as a conversion of selbri, similarly to the cmavo of selma'o SE. This conversion changes

Example 16.70:

tu'a mi rinka le nu do morsi
something-to-do-with me causes the event-of you are-dead
My action causes your death.


Example 16.71:

mi jai rinka le nu do morsi
I am-associated-with causing the event-of your death.
I cause your death.

In English, the subject of “cause” can either be the actual cause (an event), or else the agent of the cause (a person, typically); not so in Lojban, where the x1 of rinka is always an event. Example 16.70 and Example 16.71 look equally convenient (or inconvenient), but in making descriptions, Example 16.71 can be altered to:

Example 16.72:

le jai rinka be le nu do morsi
that-which-is associated-with causing (the event-of your death)
the one who caused your death

because jai modifies the selbri and can be incorporated into the description – not so for tu'a.

The weakness of jai used in descriptions in this way is that it does not specify which argument of the implicit abstraction is being raised into the x1 place of the description selbri. One can be more specific by using the modal form of jai explained in Section 13.11:

Example 16.73:

le jai gau rinka be le nu do morsi
that-which-is agent-in causing (the event-of your death)

Event-type abstractors and event contour tenses

This section is a logical continuation of Section 16.2.

There exists a relationship between the four types of events explained in Section 16.2 and the event contour tense cmavo of selma'o ZAhO. The specific cmavo of NU and of ZAhO are mutually interdefining; the ZAhO contours were chosen to fit the needs of the NU event types and vice versa. Event contours are explained in full in Section 14.9, and only summarized here.

The purpose of ZAhO cmavo is to represent the natural portions of an event, such as the beginning, the middle, and the end. They fall into several groups:

  • The cmavo pu'o, ca'o, and ba'o represent spans of time: before an event begins, while it is going on, and after it is over, respectively.
  • The cmavo co'a, de'a, di'a, and co'u represent points of time: the start of an event, the temporary stopping of an event, the resumption of an event after a stop, and the end of an event, respectively. Not all events can have breaks in them, in which case de'a and di'a do not apply.
  • The cmavo mo'u and za'o correspond to co'u and ba'o respectively, in the case of those events which have a natural ending point that may not be the same as the actual ending point: mo'u refers to the natural ending point, and za'o to the time between the natural ending point and the actual ending point (the “excessive” or “superfective” part of the event).
  • The cmavo co'i represents an entire event considered as a point-event or achievement.

All these cmavo are applicable to events seen as processes and abstracted with pu'u. Only processes have enough internal structure to make all these points and spans of time meaningful.

For events seen as states and abstracted with za'i, the meaningful event contours are the spans pu'o, ca'o, and ba'o; the starting and ending points co'a and co'u, and the achievement contour co'i. States do not have natural endings distinct from their actual endings. (It is an open question whether states can be stopped and resumed.)

For events seen as activities and abstracted with zu'o, the meaningful event contours are the spans pu'o, ca'o, and ba'o, and the achievement contour co'i. Because activities are inherently cyclic and repetitive, the beginning and ending points are not well-defined: you do not know whether an activity has truly begun until it begins to repeat.

For events seen as point-events and abstracted with mu'e, the meaningful event contours are the spans pu'o and ba'o but not ca'o (a point-event has no duration), and the achievement contour co'i.

Note that the parts of events are themselves events, and may be treated as such. The points in time may be seen as mu'e point-events; the spans of time may constitute processes or activities. Therefore, Lojban allows us to refer to processes within processes, activities within states, and many other complicated abstract things.

Abstractor connection

An abstractor may be replaced by two or more abstractors joined by logical or non-logical connectives. Connectives are explained in detail in Chapter ELG-ERROR in Template:Lch. The connection can be expanded to one between two bridi which differ only in abstraction marker. Example 16.74 and Example 16.75 are equivalent in meaning:

Example 16.74:

le ka la frank. ciska cu xlali .ije le ni la frank. ciska cu xlali
The quality-of Frank's writing is bad, and the quantity of Frank's writing is bad.
Example 16.75:

le ka je ni la frank. ciska cu xlali
The quality and quantity of Frank's writing is bad.

This feature of Lojban has hardly ever been used, and nobody knows what uses it may eventually have.

Table of abstractors

The following table gives each abstractor, an English gloss for it, a Lojban gismu which is connected with it (more or less remotely: the associations between abstractors and gismu are meant more as memory hooks than for any kind of inference), the rafsi associated with it, and (on the following line) its place structure.</para> <tab class=wikitable> cmavo selma'o subclass meaning nu event of fasnu nun

x1 is an event of (the bridi)

ka property of ckaji kam

x1 is a property of (the bridi)

ni amount of klani nil

x1 is an amount of (the bridi) measured on scale x2

jei truth-value of jetnu jez

x1 is a truth-value of (the bridi) under epistemology x2

li'i experience of lifri liz

x1 is an experience of (the bridi) to experiencer x2

si'o idea of sidbo siz

x1 is an idea/concept of (the bridi) in the mind of x2

du'u predication of ----- dum

x1 is the bridi (the bridi) expressed by sentence x2

su'u abstraction of sucta sus

x1 is an abstract nature of (the bridi)

za'i state of zasti zam

x1 is a state of (the bridi)

zu'o activity of zukte zum

x1 is an activity of (the bridi)

pu'u process of pruce pup

x1 is a process of (the bridi)

mu'e point-event of mulno mub

x1 is a point-event/achievement of (the bridi)



The picture for chapter 14

Logical connection and truth tables

Lojban is a logical language: the name of the language itself means

“logical language”. The fundamentals of ordinary logic (there are variant logics, which aren't addressed in this book) include the notions of a “sentence” (sometimes called a “statement” or “proposition”), which asserts a truth or falsehood, and a small set of “truth functions”, which combine two sentences to create a new sentence. The truth functions have the special characteristic that the truth value (that is, the truth or falsehood) of the results depends only on the truth value of the component sentences. For example,

Example 16.76:

John is a man or James is a woman.

is true if “John is a man” is true, or if “James is a woman” is true. If we know whether John is a man, and we know whether James is a woman, we know whether “John is a man or James is a woman” is true, provided we know the meaning of “or”. Here “John is a man” and “James is a woman” are the component sentences.

We will use the phrase “negating a sentence” to mean changing its truth value. An English sentence may always be negated by prefixing

“It is false that ...”, or more idiomatically by inserting “not” at the right point, generally before the verb. “James is not a woman” is the negation of “James is a woman”, and vice versa. Recent slang can also negate a sentence by following it with the exclamation “Not!”

Words like “or” are called “logical connectives”, and Lojban has many of them, as befits a logical language. This chapter is mostly concerned with explaining the forms and uses of the Lojban logical connectives. There are a number of other logical connectives in English such as “and”, “and/or”, “if”, “only if”, “whether or not”, and others; however, not every use of these English words corresponds to a logical connective. This point will be made clear in particular cases as needed. The other English meanings are supported by different Lojban connective constructs.

The Lojban connectives form a system (as the title of this chapter suggests), regular and predictable, whereas natural-language connectives are rather less systematic and therefore less predictable.

There exist 16 possible different truth functions. A truth table is a graphical device for specifying a truth function, making it clear what the value of the truth function is for every possible value of the component sentences. Here is a truth table for


<tab class=wikitable header=true> first second result True True True True False True False True True False False False </tab> This table means that if the first sentence stated is true, and the second sentence stated is true, then the result of the truth function is also true. The same is true for every other possible combination of truth values except the one where both the first and the second sentences are false, in which case the truth value of the result is also false.

Suppose that “John is a man” is true (and “John is not a man” is false), and that “James is a woman” is false (and “James is not a woman” is true). Then the truth table tells us that

“John is a man, or James is not a woman” (true true ) is true
“John is a man, or James is a woman” (true , false) is true
“John is not a man, or James is not a woman” (false, true ) is true
“John is not a man, or James is a woman” (false, false) is false

Note that the kind of “or” used in this example can also be expressed (in formal English) with “and/or”. There is a different truth table for the kind of “or” that means “either ... or ... but not both”.

To save space, we will write truth tables in a shorter format henceforth. Let the letters T and F stand for True and False. The rows will always be given in the order shown above: TT, TF, FT, FF for the two sentences. Then it is only necessary to give the four letters from the result column, which can be written TTTF, as can be seen by reading down the third column of the table above. So TTTF is the abbreviated truth table for the

“or” truth function. Here are the 16 possible truth functions, with an English version of what it means to assert that each function is, in fact, true ( “first” refers to the first sentence, and “second” to the second sentence):

<tab class=wikitable header=true> TTTT (always true) TTTF first is true and/or second is true. TTFT first is true if second is true. TTFF first is true whether or not second is true. TFTT first is true only if second is true. TFTF whether or not first is true, second is true. TFFT first is true if and only if second is true. TFFF first is true and second is true FTTT first and second are not both true. FTTF first or second is true, but not both. FTFT whether or not first is true, second is false. FTFF first is true, but second is false. FFTT first is false whether or not second is true. FFTF first is false, but second is true. FFFT neither first nor second is true. FFFF (always false) </tab> Skeptics may work out the detailed truth tables for themselves.

The Four basic vowels

Lojban regards four of these 16 truth functions as fundamental, and assigns them the four vowels A, E, O, and U. These letters do not represent actual cmavo or selma'o, but rather a component vowel from which actual logical-connective cmavo are built up, as explained in the next section. Here are the four vowels, their truth tables, and rough English equivalents:

<tab class=wikitable header=true> A TTTF or, and/or E TFFF and O TFFT if and only if U TTFF whether or not </tab> More precisely:

A is true if either or both sentences are true
E is true if both sentences are true, but not otherwise
O is true if the sentences are both true or both false
U is true if the first sentence is true, regardless of the truth value of the second sentence

With the four vowels, the ability to negate either sentence, and the ability to exchange the sentences, as if their order had been reversed, we can create all of the 16 possible truth functions except TTTT and FFFF, which are fairly useless anyway. The following table illustrates how to create each of the 14 remaining truth functions:

<tab class=wikitable header=true> TTTF A TTFT A with second sentence negated TTFF U TFTT A with first sentence negated TFTF U with sentences exchanged TFFT O TFFF E FTTT A with both sentences negated FTTF O with either first or second negated (not both) FTFT U with sentences exchanged and then second negated FTFF E with second sentence negated FFTT U with first sentence negated FFTF E with first sentence negated FFFT E with both sentences negated </tab> Note that exchanging the sentences is only necessary with U. The three other basic truth functions are commutative; that is, they mean the same thing regardless of the order of the component sentences. There are other ways of getting some of these truth tables; these just happen to be the methods usually employed.

The six types of logical connectives

In order to remain unambiguous, Lojban cannot have only a single logical connective for each truth function. There are many places in the grammar of the language where logical connection is permitted, and each must have its appropriate set of connectives. If the connective suitable for sumti were used to connect selbri, ambiguity would result.

Consider the English sentence:

Example 16.77:

Mary went to the window and ...

where the last word could be followed by “the door”, a noun phrase, or by “saw the horses”, a sentence with subject omitted, or by “John went to the door”, a full sentence, or by one of a variety of other English grammatical constructions. Lojban cannot tolerate such grammatical looseness.

Instead, there are a total of five different selma'o used for logical connection: A, GA, GIhA, GUhA, and JA. Each of these includes four cmavo, one based on each of the four vowels, which is always the last vowel in the cmavo. In selma'o A, the vowel is the entire cmavo.

Thus, in selma'o A, the cmavo for the function A is a. (Do not confuse A, which is a selma'o, with A, which is a truth function, or a, which is a cmavo.) Likewise, the cmavo for E in selma'o GIhA is gi'e, and the cmavo for U in selma'o GA is gu. This systematic regularity makes the cmavo easier to learn.

Obviously, four cmavo are not enough to express the 14 truth functions explained in Section 16.13. Therefore, compound cmavo must be used. These compound cmavo follow a systematic pattern: each has one cmavo from the five logical connection selma'o at its heart, and may also contain one or more of the auxiliary cmavo se, na, or nai. Which auxiliaries are used with which logical connection cmavo, and with what grammar and meaning, will be explained in the following sections. The uses of each of these auxiliary cmavo relates to its other uses in other parts of Lojban grammar.

For convenience, each of the types of compound cmavo used for logical connection is designated by a Lojban name. The name is derived by changing the final “-A” of the selma'o name to “-ek”; the reasons for using “-ek” are buried deep in the history of the Loglan Project. Thus, compound cmavo based on selma'o A are known as eks, and those based on selma'o JA are known as jeks. (When writing in English, it is conventional to use “eks” as the plural of “ek”.) When the term “logical connective” is used in this chapter, it refers to one or more of these kinds of compound cmavo.

Why does the title of this section refer to “six types” when there are only five selma'o? A jek may be preceded by i, the usual Lojban cmavo for connecting two sentences. The compound produced by i followed by a jek is known as an ijek. It is useful to think of ijeks as a sixth kind of logical connective, parallel to eks, jeks, geks, giheks, and guheks.

There also exist giks, joiks, ijoiks, and joigiks, which are not logical connectives, but are other kinds of compound cmavo which will be introduced later.

Logical connection of bridi

Now we are ready to express Example 16.76 in Lojban! The kind of logical connective which is placed between two Lojban bridi to connect them logically is an ijek:

Example 16.78:

la djan. nanmu .ija la djeimyz. ninmu
John is-a-man or James is-a-woman.

Here we have two separate Lojban bridi, la djan. nanmu' and la djeimyz. ninmu. These bridi are connected by .i'ja, the ijek for the truth function A. The i portion of the ijek tells us that we are dealing with separate sentences here. Similarly, we can now say:

Example 16.79:

la djan. nanmu .ije la djeimyz. ninmu
John is-a-man and James is-a-woman.
Example 16.80:

la djan. nanmu .ijo la djeimyz. ninmu
John is-a-man if-and-only-if James is-a-woman.
Example 16.81:

la djan. nanmu .iju la djeimyz. ninmu
John is-a-man whether-or-not James is-a-woman.

To obtain the other truth tables listed in

Section 16.14, we need to know how to negate the two bridi which represent the component sentences. We could negate them directly by inserting na before the selbri, but Lojban also allows us to place the negation within the connective itself.

To negate the first or left-hand bridi, prefix na to the JA cmavo but after the i. To negate the second or right-hand bridi, suffix

-nai to the JA cmavo. In either case, the negating word is placed on the side of the connective that is closest to the bridi being negated.

So to express the truth table FTTF, which requires O with either of the two bridi negated (not both), we can say either:

Example 16.82:

la djan. nanmu .inajo la djeimyz. ninmu
John is-not-a-man if-and-only-if James is-a-woman.
Example 16.83:

la djan. nanmu .ijonai la djeimyz. ninmu
John is a man if-and-only-if James is-not-a-woman

The meaning of both Example 16.82 and Example 16.83 is the same as that of:

Example 16.84:

John is a man or James is a woman, but not both.

Here is another example:

Example 16.85:

la djan. nanmu .ijanai la djeimyz. ninmu
John is-a-man or James is-not-a-woman.
John is a man if James is a woman.

How's that again? Are those two English sentences in Example 16.85 really equivalent? In English, no. The Lojban TTFT truth function can be glossed “A if B”, but the “if” does not quite have its English sense. Example 16.85 is true so long as John is a man, even if James is not a woman; likewise, it is true just because James is not a woman, regardless of John's gender. This kind of “if-then” is technically known as a “material conditional”.

Since James is not a woman (by our assertions in Section 16.13), the English sentence “John is a man if James is a woman” seems to be neither true nor false, since it assumes something which is not true. It turns out to be most convenient to treat this “if” as TTFT, which on investigation means that Example 16.85 is true. Example 16.86, however, is equally true:

Example 16.86:

la djan. ninmu .ijanai la djeimyz. ninmu
John is a woman if James is a woman.

This can be thought of as a principle of consistency, and may be paraphrased as follows:

“If a false statement is true, any statement follows from it.” All uses of English “if” must be considered very carefully when translating into Lojban to see if they really fit this Lojban mold.

Example 16.87, which uses the TFTT truth function, is subject to the same rules: the stated gloss of TFTT as “only if” works naturally only when the right-hand bridi is false; if it is true, the left-hand bridi may be either true or false. The last gloss of Example 16.87 illustrates the use of “if ... then” as a more natural substitute for “only if”.

Example 16.87:

la djan. nanmu .inaja la djeimyz. ninmu
John is-not-a-man or James is-a-woman.
John is a man only if James is a woman.
If John is a man, then James is a woman.

The following example illustrates the use of se to, in effect, exchange the two sentences. The normal use of se is to (in effect) transpose places of a bridi, as explained in Section 6.10.

Example 16.88:

la djan. nanmu .iseju la djeimyz. ninmu
Whether or not John is a man, James is a woman.

If both na and se are present, which is legal but never necessary, na would come before se.

The full syntax of ijeks, therefore, is:

.i [na] [se] JA [nai] where the cmavo in brackets are optional.

Forethought bridi connection

Many concepts in Lojban are expressible in two different ways, generally referred to as “afterthought” and “forethought”. Section 16.16 discussed what is called “afterthought bridi logical connection”. The word

“afterthought” is used because the connective cmavo and the second bridi were added, as it were, afterwards and without changing the form of the first bridi. This form might be used by someone who makes a statement and then wishes to add or qualify that statement after it has been completed. Thus,

Example 16.89:

la djan. nanmu

is a complete bridi, and adding an afterthought connection to make

Example 16.90:

la djan. nanmu .ija la djeimyz. ninmu
John is a man or James is a woman (or both)

provides additional information without requiring any change in the form of what has come before; changes which may not be possible or practical, especially in speaking. (The meaning, however, may be changed by the use of a negating connective.) Afterthought connectives make it possible to construct all the important truth-functional relationships in a variety of ways.

In forethought style the speaker decides in advance, before expressing the first bridi, that a logical connection will be expressed. Forethought and afterthought connectives are expressed with separate selma'o. The forethought logical connectives corresponding to afterthought ijeks are geks:

Example 16.91:

ga la djan. nanmu gi la djeimyz. ninmu
Either John is a man or James is a woman (or both).

ga is the cmavo which represents the A truth function in selma'o GA. The word gi does not belong to GA at all, but constitutes its own selma'o: it serves only to separate the two bridi without having any content of its own. The English translation of gagi is “either ... or”, but in the English form the truth function is specified both by the word “either” and by the word “or”: not so in Lojban.

Even though two bridi are being connected, geks and giks do not have any

i in them. The forethought construct binds up the two bridi into a single sentence as far as the grammar is concerned.

Some more examples of forethought bridi connection are:

Example 16.92:

ge la djan. nanmu gi la djeimyz. ninmu
(It is true that) both John is a man and James is a woman.
Example 16.93:

gu la djan. nanmu gi la djeimyz. ninmu
It is true that John is a man, whether or not James is a woman.

It is worth emphasizing that Example 16.93 does not assert that James is (or is not) a woman. The gu which indicates that

la djeimyz. ninmu may be true or false is unfortunately rather remote from the bridi thus affected.

Perhaps the most important of the truth functions commonly expressed in forethought is TFTT, which can be paraphrased as “if ... then ...”:

Example 16.94:

ganai la djan. nanmu gi la djeimyz. ninmu
Either John is not a man, or James is a woman.
If John is a man, then James is a woman.

Note the placement of the nai in Example 16.94. When added to afterthought selma'o such as JA, a following nai negates the second bridi, to which it is adjacent. Since GA cmavo precede the first bridi, a following nai negates the first bridi instead.

Why does English insist on forethought in the translation of Example 16.94? Possibly because it would be confusing to seemingly assert a sentence and then make it conditional (which, as the Lojban form shows, involves a negation). Truth functions which involve negating the first sentence may be confusing, even to the Lojbanic understanding, when expressed using afterthought.

It must be reiterated here that not every use of English “if ... then” is properly translated by

.i'na'ja or ganaigi; anything with implications of time needs a somewhat different Lojban translation, which will be discussed in Section 16.30. Causal sentences like “If you feed the pig, then it will grow” are not logical connectives of any type, but rather need a translation using

rinka as the selbri joining two event abstractions, thus:

Example 16.95:

le nu do cidja dunda fi le xarju cu rinka le nu ri ba banro
The event-of (you food-give to the pig) causes the event-of (it will grow).

Causality is discussed in far more detail in Section 13.6.

Example 16.96 and Example 16.97 illustrates a truth function, FTTF, which needs to negate either the first or the second bridi. We already understand how to negate the first bridi:

Example 16.96:

gonai la djan. nanmu gi la djeimyz. ninmu
John is-not-a-man if-and-only-if James is-a-woman.
Either John is a man or James is a woman but not both.

How can the second bridi be negated? By adding

-nai to the


Example 16.97:

go la djan. nanmu ginai la djeimyz. ninmu
John is-a-man if-and-only-if James is-not-a-woman.
Either John is a man or James is a woman but not both.

A compound cmavo based on gi is called a gik; the only giks are

gi itself and 'gi'nai.

Further examples:

Example 16.98:

ge la djan. nanmu ginai la djeimyz. ninmu
John is-a-man and James is-not-a-woman.
Example 16.99:

ganai la djan. nanmu ginai la djeimyz. ninmu
John is-not-a-man or James is-not-a-woman.

The syntax of geks is:

[se] GA [nai] and of giks (which are not themselves connectives, but part of the machinery of forethought connection) is:

gi [nai]

sumti connection

Geks and ijeks are sufficient to state every possible logical connection between two bridi. However, it is often the case that two bridi to be logically connected have one or more portions in common:

Example 16.100:

la djan. klama le zarci .ije la .alis. klama le zarci
John goes to the market, and Alice goes to the market.

Here only a single sumti differs between the two bridi. Lojban does not require that both bridi be expressed in full. Instead, a single bridi can be given which contains both of the different sumti and uses a logical connective from a different selma'o to combine the two sumti:

Example 16.101:

la djan .e la .alis. klama le zarci
John and Alice go-to the market.

Example 16.101 means exactly the same thing as Example 16.100: one may be rigorously transformed into the other without any change of logical meaning. This rule is true in general for every different kind of logical connection in Lojban; all of them, with one exception (See Section 16.24), can always be transformed into a logical connection between sentences that expresses the same truth function.

The afterthought logical connectives between sumti are eks, which contain a connective cmavo of selma'o A. If ijeks were used in Example 16.101, the meaning would be changed:

Example 16.102:

la djan. .ije la .alis. klama le zarci
John [is/does something]. And Alices goes-to the market.

leaving the reader uncertain why John is mentioned at all.

Any ek may be used between sumti, even if there is no direct English equivalent:

Example 16.103:

la djan. .o la .alis. klama le zarci
John if-and-only-if Alice goes-to the market.
John goes to the market if, and only if, Alice does.

The second line of Example 16.102 is highly stilted English, but the first line (of which it is a literal translation) is excellent Lojban.

What about forethought sumti connection? As is the case for bridi connection, geks are appropriate. They are not the only selma'o of forethought logical-connectives, but are the most commonly used ones.

Example 16.104:

ga la djan. gi la .alis. klama le zarci
Either John or Alice (or both) goes-to the market.

Of course, eks include all the same patterns of compound cmavo that ijeks do. When na or se is part of an ek, a special writing convention is invoked, as in the following example:

Example 16.105:

la djan. na.a la .alis. klama le zarci
John only if Alice goes-to the market.
John goes to the market only if Alice does.

Note the period in 'na'.a. The cmavo of A begin with vowels, and therefore must always be preceded by a pause. It is conventional to write all connective compounds as single words (with no spaces), but this pause must still be marked in writing as in speech; otherwise, the na and a would tend to run together.

More than two propositions

So far we have seen logical connectives used to connect exactly two sentences. How about connecting three or more? Is this possible in Lojban? The answer is yes, subject to some warnings and some restrictions.

Of the four primitive truth functions A, E, O, and U, all but O have the same truth values no matter how their component sentences are associated in pairs. Therefore,

Example 16.106:

mi dotco .ije mi ricfu .ije mi nanmu
I am-German. And I am-rich. And I am-a-man.

means that all three component sentences are true. Likewise,

Example 16.107:

mi dotco .ija mi ricfu .ija mi nanmu
I am-German. Or I am-rich. Or I am-a-man.

means that one or more of the component sentences is true.

O, however, is different. Working out the truth table for

Example 16.108:

mi dotco .ijo mi ricfu .ijo mi nanmu
I am-German. If-and-only-if I am-rich. If-and-only-if I am-a-man.

shows that Example 16.108 does not mean that either I am all three of these things or none of them; instead, an accurate translation would be:

Of the three properties – German-ness, wealth, and manhood – I possess either exactly one or else all three.

Because of the counterintuitiveness of this outcome, it is safest to avoid O with more than two sentences. Likewise, the connectives which involve negation also have unexpected truth values when used with more than two sentences.

In fact, no combination of logical connectives can produce the “all or none” interpretation intended (but not achieved) by Example 16.108 without repeating one of the bridi. See Example 16.123.

There is an additional difficulty with the use of more than two sentences. What is the meaning of:

Example 16.109:

mi nelci la djan. .ije mi nelci la martas. .ija mi nelci la meris.
I like John. And I like Martha. Or I like Mary.

Does this mean:

Example 16.110:

I like John, and I like either Martha or Mary or both.

Or is the correct translation:

Example 16.111:

Either I like John and I like Martha, or I like Mary, or both.

Example 16.111 is the correct translation of Example 16.109. The reason is that Lojban logical connectives pair off from the left, like many constructs in the language. This rule, called the left-grouping rule, is easy to forget, especially when intuition pulls the other way. Forethought connectives are not subject to this problem:

Example 16.112:

ga ge mi nelci la djan. gi mi nelci la martas. gi mi nelci la meris.
Either (Both I like John and I like Martha) or I like Mary.

is equivalent in meaning to Example 16.109, whereas

Example 16.113:

ge mi nelci la djan. gi ga mi nelci la martas. gi mi nelci la meris.
Both I like John and (Either I like Martha or I like Mary).

is not equivalent to Example 16.109, but is instead a valid translation into Lojban, using forethought, of Example 16.110.

Grouping of afterthought connectives

There are several ways in Lojban to render Example 16.110 using afterthought only. The simplest method is to make use of the cmavo bo (of selma'o BO). This cmavo has several functions in Lojban, but is always associated with high precedence and short scope. In particular, if bo is placed after an ijek, the result is a grammatically distinct kind of ijek which overrides the regular left-grouping rule. Connections marked with bo are interpreted before connections not so marked. Example 16.114 is equivalent in meaning to Example 16.113:

Example 16.114:

mi nelci la djan. .ije mi nelci la martas. .ijabo mi nelci la meris.
I like John, and I like Martha or I like Mary.

The English translation feebly indicates with a comma what the Lojban marks far more clearly: the “I like Martha” and “I like Mary” sentences are joined by '.i'ja first, before the result is joined to “I like John” by '.i'je.

Eks can have bo attached in exactly the same way, so that Example 16.115 is equivalent in meaning to Example 16.114:

Example 16.115:

mi nelci la djan. .e la martas. .abo la meris.

Forethought connectives, however, never can be suffixed with bo, for every use of forethought connectives clearly indicates the intended pattern of grouping.

What happens if bo is used on both connectives, giving them the same high precedence, as in Example 16.116?

Example 16.116:

mi nelci la djan. .ebo la martas. .abo la meris.

Does this wind up meaning the same as Example 16.109 and Example 16.111? Not at all. A second rule relating to bo is that where several bo-marked connectives are used in succession, the normal Lojban left-grouping rule is replaced by a right-grouping rule. As a result,

Example 16.116 in fact means the same as Example 16.114 and Example 16.115. This rule may be occasionally exploited for special effects, but is tricky to keep straight; in writing intended to be easy to understand, multiple consecutive connectives marked with bo should be avoided.

The use of bo, therefore, gets tricky in complex connections of more than three sentences. Looking back at the English translations of Example 16.112 and Example 16.113, parentheses were used to clarify the grouping. These parentheses have their Lojban equivalents, two sets of them actually. tu'e and tu'u are used with ijeks, and ke and ke'e with eks and other connectives to be discussed later. ( ke and ke'e are also used in other roles in the language, but always as grouping markers). Consider the English sentence:

Example 16.117:

I kiss you and you kiss me, if I love you and you love me.

where the semantics tells us that the instances of “and” are meant to have higher precedence than that of “if”. If we wish to express Example 16.117 in afterthought, we can say:

Example 16.118:

mi cinba do .ije[bo] do cinba mi .ijanai mi prami do .ijebo do prami mi
I kiss you and you kiss me, if I love you and you love me.

marking two of the ijeks with bo for high precedence. (The first bo is not strictly necessary, because of the left-grouping rule, and is shown here in brackets.)

But it may be clearer to use explicit parenthesis words and say:

Example 16.119:

tu'e mi cinba do .ije do cinba mi tu'u .ijanai tu'e mi prami do .ije do prami mi [tu'u]
( I kiss you and you kiss me ) if ( I love you and you love me ).

where the tu'etu'u pairs set off the structure. The cmavo tu'u is an elidable terminator, and its second occurrence in Example 16.119 is bracketed, because all terminators may be elided at the end of a text.

In addition, parentheses are a general solution: multiple parentheses may be nested inside one another, and additional afterthought material may be added without upsetting the existing structure. Neither of these two advantages apply to bo grouping. In general, afterthought constructions trade generality for simplicity.

Because of the left-grouping rule, the first set of tu'etu'u parentheses may actually be left off altogether, producing:

Example 16.120:

mi cinba do .ije do cinba mi .ijanai tu'e mi prami do .ije do prami mi [tu'u]
I kiss you and you kiss me if ( I love you and you love me ).

What about parenthesized sumti connection? Consider

Example 16.121:

I walk to either the market and the house, or the school and the office.

Two pairs of parentheses, analogous to Example 16.119, would seem to be the right approach. However, it is a rule of Lojban grammar that a sumti may not begin with ke, so the first set of parentheses must be omitted, producing Example 16.122, which is instead parallel to Example 16.120:

Example 16.122:

mi dzukla le zarci .e le zdani .a ke le ckule .e le briju [ke'e]
I walk-to the market and the house or ( the school and the office ).

If sumti were allowed to begin with ke, unavoidable ambiguities would result, so ke grouping of sumti is allowed only just after a logical connective. This rule does not apply to tu'e grouping of bridi, as Example 16.119 shows.

Now we have enough facilities to handle the problem of Example 16.108: “I am German, rich, and a man – or else none of these.” The following paraphrase has the correct meaning:

Example 16.123:

[tu'e] mi dotco .ijo mi ricfu [tu'u] .ije tu'e mi dotco .ijo mi nanmu [tu'u]
( I am-German if-and-only-if I am-rich ) and (I am-German if-and-only-if I am-a-man ).

The truth table, when worked out, produces T if and only if all three component sentences are true or all three are false.

Compound bridi

So far we have seen how to handle two sentences that need have no similarity at all (bridi connection) and sentences that are identical except for a difference in one sumti (sumti connection). It would seem natural to ask how to logically connect sentences that are identical except for having different selbri.

Surprise! Lojban provides no logical connective that is designed to handle selbri and nothing else. Instead, selbri connection is provided as part of a more general-purpose mechanism called “compound bridi”. Compound bridi result from logically connecting sentences that differ in their selbri and possibly some of their sumti.

The simplest cases result when the x1 sumti is the only common point:

Example 16.124:

mi klama le zarci .ije mi nelci la djan.
I go to the market, and I like John.

is equivalent in meaning to the compound bridi:

Example 16.125:

mi klama le zarci gi'e nelci la djan.
I go-to the market and like John.

As Example 16.125 indicates, giheks are used in afterthought to create compound bridi;

gi'e is the gihek corresponding to “and”. The actual phrases

klama le zarci and
nelci la djan. that the gihek connects are known as

“bridi-tails”, because they represent (in this use) the “tail end” of a bridi, including the selbri and any following sumti, but excluding any sumti that precede the selbri:

Example 16.126:

mi ricfu gi'e klama le zarci
I am-rich and go-to the market.

In Example 16.126, the first bridi-tail is ricfu, a simple selbri, and the second bridi-tail is

klama le zarci, a selbri with one following sumti.

Suppose that more than a single sumti is identical between the two sentences:

Example 16.127:

mi dunda le cukta do .ije mi lebna lo rupnu do
I give the book to-you, and I take some currency-units from-you.

In Example 16.127, the first and last sumti of each bridi are identical; the selbri and the second sumti are different. By moving the final sumti to the beginning, a form analogous to Example 16.125 can be achieved:

Example 16.128:

fi do fa mi dunda le cukta gi'e lebna lo rupnu
to/from you I give the book and take some currency-units.

where the fi does not have an exact English translation because it merely places do in the third place of both lebna and dunda. However, a form that preserves natural sumti order also exists in Lojban. Giheks connect two bridi-tails, but also allow sumti to be added following the bridi-tail. These sumti are known as tail-terms, and apply to both bridi. The straightforward gihek version of Example 16.127 therefore is:

Example 16.129:

mi dunda le cukta gi'e lebna lo rupnu vau do
I (give the book) and (take some currency-units) to/from you.

The vau (of selma'o VAU) serves to separate the bridi-tail from the tail-terms. Every bridi-tail is terminated by an elidable vau, but only in connection with compound bridi is it ever necessary to express this

vau. Thus:

Example 16.130:

mi klama le zarci [vau]
I go-to the market.

has a single elided vau, and Example 16.125 is equivalent to:

Example 16.131:

mi klama le zarci [vau] gi'e nelci la djan. [vau] [vau]

where the double vau at the end of Example 16.131 terminates both the right-hand bridi-tail and the unexpressed tail-terms.

A final use of giheks is to combine bridi-tails used as complete sentences, the Lo