Adjectival noun (Japanese)

In descriptions of the Japanese language, an adjectival noun, adjectival, or na-adjective is a noun that can function as an adjective by taking the particle 〜な -na. (In comparison, regular nouns can function adjectivally by taking the particle 〜の -no, which is analyzed as the genitive case.) Adjectival nouns constitute one of several Japanese word classes that can be considered equivalent to adjectives.

In their attributive function, Japanese adjectival nouns function similarly to English noun adjuncts, as in "chicken soup" or "winter coat" – in these cases, the nouns "chicken" and "winter" modify the nouns "soup" and "coat", respectively. Japanese adjectival nouns can also be used predicatively – in that use, they do not take the -na suffix, but normally combine with forms of the copular verb.