Are verbs, nouns and adjectives real?
Written by la gleki :
Lojban has no "verb vs. noun vs. adjective" distinction. For example, mlatu means to be a cat but in order to convert it to a noun you just add lo in front of it. Likewise, to convert it into an adjective you prefix it with poi.
mlatu = to be a cat
lo mlatu = cat, cats
poi mlatu = which is a cat
However, in many languages many words are nouns, verbs or adjectives by default.
There isn't a unified criterion of what the terms verb, noun and adjective mean. One will have to apply different criteria for different languages. For example, here is what is believed to be noun:
- Greek Noun (Dionysius Thrax, Ars minor, 2nd c. BCE)
- ὄνομά ἐστι μέρος λόγου πτωτικόν, σῶμα ἢ πρᾶγμα σημαῖνον
- "Noun is a case-inflected part of speech that denotes a thing or an action."
- English Noun (Quirk et al. 1985: 72)
- "Noun is a word that can follow determiners like the, this and that."
- Mandarin Chinese Noun
- "Noun is a word that can follow a classifier."
Haspelmath claims  that the following classification is to be applied:
- thing-root: a root that denotes a physical object (animate or inanimate)
- action-root: a root that denotes a volitional action
- property-root: a root that denotes a property such as age, dimension or value
and more precisely:
- nouns are roots used for reference without special coding (reference-roots)
- verbs are roots used for predication without special coding (predication-roots)
- adjectives are roots used for attribution without special coding (attribution-roots)
- manner adverbs are roots used for adverbation without special coding (adverbation-roots)
This is based on an assumption that e.g. in Tagalog action-roots take aspect-modality inflection and voice affixes (e.g. the prefix nag-), while thing-roots do not have these possibilities.
This leads Haspelmath to an idea that his classification of parts of speech is useful.
Useful or not it simply represents a very simple semantic categorization of roots.
The lack of aspect-modality on "action-roots" can be explained by the simple semantic incompatibility and usage of those words in real life.
Likewise, we can split roots into other classes based on other criteria.
Other than that there is no difference between those roots in Tagalog. They are perfectly in line with how Lojban works.
William Croft's view
Words that translate into English as nouns, adjectives, and adverbs, as well as verbs, are inflected for person, aspect, and mood in Makah, an American Indian language, and that no words are inflected for these categories in Vietnamese. He points out that therefore tense-aspect-mood inflection cannot be taken as critical for determining the category of verb crosslinguistically (unless, of course, one is willing to say that all words are verbs in Makah, and no words are verbs in Vietnamese). No syntactic test will pick out all and only entities that one might wish to call verbs, nouns, adjectives, subjects, or objects across all languages. Moreover, he observes, that even within a single language, a given criterion often only applies within certain larger constructions. For example, if one takes passivizability as the criterion for Direct Object in English, then one's conclusions will tell us something about the Passive, not about some allegedly global category Direct Object. Constructions, not categories or relations, are the basic, primitive units of syntactic representation.
- Croft, William. Radical Construction Grammar: Syntactic Theory in Typological Perspective. Oxford: Oxford University Press, 2001