Japanese adjectives

The Japanese language does not have words that function as adjectives in a syntactic sense – that is to say that tree diagrams of Japanese sentences can be constructed without employing adjective phrases. Nevertheless, there are words that function as adjectives in a semantic sense. This article deals with those words.

In Japanese, nouns and verbs can modify nouns, with nouns taking the 〜の particles when functioning attributively (in the genitive case), and verbs in the attributive form (連体形 rentaikei). These are considered separate classes of words, however.

Most of the words that can be considered to be adjectives in Japanese fall into one of two categories – variants of verbs, and nouns:

Both the predicative forms (終止形 shūshikei "terminal form") and attributive forms (連体形 rentaikei) of adjectival verbs and adjectival nouns can be analyzed as verb phrases, making the attributive forms of adjectival verbs and adjectival nouns relative clauses, rather than adjectives. According to this analysis, Japanese has no syntactic adjectives.

Japanese adjectives that do not fall into either of these categories are usually grouped into a grab-bag category:

A couple of small sub-categories can be distinguished in these categories, reflecting former grammatical distinctions or constructions which no longer exist:

Adjectival verbs (形容詞 keiyōshi) end with い i (but never えい ei) in base form. They may predicate sentences and inflect for past, negative, etc. As they head verb phrases, they can be considered a type of verbal (verb-like part of speech). Their inflections are different and not so numerous as full verbs. Conversely, the negative plain form of a verb is an adjective: it ends in 〜ない -na-i, which then inflects as an i-adjective.

The stem of i-adjectives can combine (prepend on the left), similar to the stem form (-masu stem) of verbs, though this is less common than for verbs. Conversely, nouns or verb stems can sometimes prepend i-adjectives, or two i-adjectives can combine, forming compound modifiers; these are much less common than Japanese compound verbs. Common examples include omo-shiro-i (面白い^?, interesting) "face-whitening" (noun + i-adjective) and zuru-gashiko-i (狡賢い^?, sly) "crafty-clever" (i-adjective stem + i-adjective), while haya-tochiri (早とちり^?, going off half-cocked) "fast-fumble" (i-adjective stem + verb stem) shows an adjective stem joining to form a noun.

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