There is no distinction, in the form of the words, between adjectives and adverbs in Vayoti, the way there is in English (beautiful/beautifully; good/well) and many other languages.
All the Vayoti words we would call "adjectives" or "adverbs" come under a common heading: Modifiers.
A modifier cannot be identified, apart from a grammatical context, as either an adjective or adverb. Its adjectival or adverbial function is determined by its actual usage in a sentence.
A Modifier is functioning adjectivally either when it:
a) follows the verb To Be or some other "stative" verb (he is good; you look sick; she seems happy). In English these are predicate adjectives.
b) The other kind of adjective is an attributive adjective, which, in English, rather than following a stative verb, is placed directly in front of the noun (a good man; a sick boy; a happy lady). In Vayoti a Modifier functions as an attributive adjective when the particle (adjective marker) ste is placed after the noun and then the adjective.
A Modifier is functioning adverbially when it follows a verb. The Adverbial Modifier needs no other grammatical component (like the adj. marker ste) to mark it out as adverbial. It is the absence of any other marker and the Modifier's position after a verb that clearly register it as adverbial in function, i.e., "describing" the action.
Technically speaking, every Modifier can function both adjectivally or adverbially. Practically speaking, common sense dictates that adverbs fashioned from such concepts as "brown" (brownly?) or "tall" (tall-ly?) are nonsensical. Common sense will guide the speaker in this matter.
That said, the fact that every modifier could theoretically serve as either an adjective or adverb does offer creative possibilities, even poetic ones.
The Classes of Modifiers
Though there are exceptions and irregular forms, it may be safely said that Modifiers generally fall into five classes, as defined by their endings:
a. 1st class: “non-derived” with the ending -kis
b. 2nd class: derived from nouns, ending in -laf
c. 3rd class: derived from verbs, ending in -sek
d. 4th class: the Perfective Adjectival Participle, ending in -tu (see Verbs)
e. 5th class: no ending ("irregular")
A "non-derived" Modifier is literally that: a Modifier that does not owe its origin, i.e., is not "taken from," a different grammatical form like a noun or verb. It is, in a manner of speaking, an "original" Modifier.
These classes are fairly regular, though there are exceptions, i.e., where a Modifier originating in, say, a noun may present the ending -sek, or a Modifier originating in a verb may present the ending -kis.
