Modern Lojban Theory (draft)

This document is maintained by spheniscine "amphora" gmail.com ; please submit corrections or comments. However, if I do not respond for a few days, please feel free to make the changes on your own, if this document should no longer reflect the most current thought.

Preface

This document is meant to describe the theory of the modern dialect of Lojban. It is meant to parallel/supplement the Complete Lojban Language, but better-reflecting the modern common-usage of phrases and sentence constructions, as well as the various changes in the grammar that have occurred since it was published.

This document is meant to be a reference, mostly for intermediate-to-advanced learners. A beginner might be able to learn the language from this document, however the Lojban Wave Lessons or the Crash Course might be more suitable for picking up conversational skill effectively.

Orthography and Phonology

Lojban has 26 phonemes; 6 vowels, 18 consonants, and 2 semivowels. Each phoneme is represented by a single letter (in some Lojban documentation, you will find the word "letteral" being used to describe letters), with two exceptions: i and u become semivowels when they begin a syllable that contains a second vowel letter. This is, however, completely predictable from the spelling of the word (more on that in the phonotactics section); thus, Lojban spelling is completely regular.

Thus, Lojban has 24 letters: 6 vowels (with 2 that can become semivowels) and 18 consonants.

The vowel letters are: a e i o u y

The consonant letters are: b c d f g j k l m n p r s t v x z ' (yes, that's the apostrophe)

Thus, the Lojban alphabet is the English alphabet, except it lacks h, q, or w, considers y a vowel, and considers the apostrophe a letter.

Additionally, the . (period) and the , (comma) are sometimes seen as "auxiliary characters". The period marks a mandatory pause or glottal stop. The comma is sometimes used within words to separate syllables where their separation may be unclear to a less-experienced Lojbanist, e.g. crenzu,ue ("to practice"). These, however, are optional and, again, completely predictable from the spelling/phonotactics of the word.

Some phonemes have allophones (different realizations of what is considered the same "sound" in the language), allowed either as a natural variation due to influence by surrounding phonemes, or to accomodate Lojban learners who speak different languages.

Below are a list of phonemes and their realizations in the IPA (International Phonetic Alphabet). IPA symbols alternate allophones are in (parentheses); preferred ones have no parentheses.

Letter	Lojban name	IPA representation(s)	Notes
a	.a bu / .a'y.	a (ɑ)	Like a as in father. Avoid "reducing" it like a as in about, as that might cause confusion with y.
b	by.	b	Like b as in bed
c	cy.	ʃ (ʂ)	Like sh as in ship. The digraph tc maps to [tʃ] and sounds like ch as in church
d	dy.	d	Like d as in dog
e	.e bu / .e'y.	ɛ	Like e as in get. Try to pronounce it in a pure, medium-high tone (closer to rare and not to rate), to avoid possible confusion with the ei diphthong.
f	fy.	f (ɸ)	Like f as in fox
g	gy.	ɡ	Like "hard" g as in get (never "soft" g as in giraffe)
i	.i bu / .i'y.	i	Like ee as in see (avoid i as in hit)
		j	[if beginning a syllable that contains another vowel] Like y as in yes. Hence .iu sounds like the English word "you"
j	jy.	ʒ (ʐ)	Like the "zh" sound of si as in vision, or the end of montage. The digraph dj maps to [dʒ] and sounds like j as in judge
k	ky.	k	Like k as in kick
l	ly.	l	Like l as in land
m	my.	m	Like m as in mom
n	ny.	n	Like n as in nun
		(ŋ)	Allowable natural variation before letters k, g, and x. Like as in skunk or finger.
o	.o bu / .o'y.	o (ɔ)	Like o as in boat. Try to keep a "pure" sound, rather than completing the diphthong; however, Lojban has no ou diphthong, so there is less risk of misunderstanding.
p	py.	p	Like p as in pen
r	ry.	r (ɹ)	Like r as in three. A "trilled r" is preferred, but isn't necessary.
s	sy.	s	Like s as in sack
t	ty.	t	Like t as in tack
u	.u bu / .u'y.	u	Like oo as in too.
		w	[if beginning a syllable that contains another vowel] Like w as in weed. Hence .uu sounds like English "woo"
v	vy.	v	Like v as in vow
x	xy.	x	Like ch as in Scottish loch. English speakers may find this sound hard to pronounce. Try saying ksss while keeping your tongue down.
y	.y bu (never .y'y.)	ə	Like a as in about
z	zy.	z	Like z as in zoo
'	.y'y.	h (θ)	Like h as in ahoy. Only ever occurs in the middle of words, and only between two vowels. Some people pronounce it as th as in thigh.

Sometimes, i and u are written with breve diacritics when they act as semivowels, e.g. .ĭu and .ŭu , but this is optional.

There are four diphthongs (glides between one vowel to another, like English sigh and how) in Lojban:

Diphthong	IPA representation(s)	Notes
ai	ai, (aj)	Like English eye
au	au, (aw)	Like English how
ei	ɛi, (ei, ɛj, ej)	Like English hey
oi	oi, (oj, ɔi, ɔj)	Like English boy

Phonotactics

Phonotactics are the rules that say what combinations of sounds are allowed. For example, /ps/ and /zd/ are combinations that English words can end with (e.g. hops, housed), but not start with. These rules apply to all Lojban words, even in the most flexible cmevla morphological class (see the Morphology section for what that means), allocated for use for proper names.

The consonants of Lojban can be divided into two groups: sonorants, and obstruents. Obstruents can be further divided into voiced and unvoiced obstruents. Which group a consonant is in is important to describe the phonotactics of Lojban.

The sonorants are: l m n r. The difference between sonorants and obstruents is that you can "sing"/hold a note with a sonorant just like you could a vowel, but you can't do so with an obstruent.
The voiced obstruents are: b d g v j z
The unvoiced obstruents are: p t k f c s x

Did we forget the apostrophe? ... well it is not considered to be in any one of these three categories. In fact, the apostrophe often doesn't act like any other Lojban consonants do. The apostrophe stands alone; it only ever occur in the middle of words, and only between two vowels.

Anyway, these three groups define what consonant clusters (combinations of consonants) are allowed.

The first rule is that no consonant can ever be doubled.
The second rule is that a voiced obstruent can never be next to an unvoiced obstruent. For example, bf is forbidden, and so is sd, but since sonorants do not have this rescrition, fl, vl, ls, and lz are all permitted.
The third rule is that no two sibilants can ever be next to each other. The sibilants are: c, j, s, z
The fourth rule is that these specific pairs are explicitly forbidden: cx, kx, xc, xk, mz

todo: stuff about initial consonant pairs, triplets, syllabic sonorants, and semivowel resolution