Inflection
Adjectival verbs (i-adjectives) are inflected by dropping the -i from the end and replacing it with the appropriate ending. Adjectival nouns (na-adjectives) are inflected by dropping the -na and replacing it with the appropriate form of the verb da, the copula.
| present | past | present neg. | past neg. | |
|---|---|---|---|---|
| i adjective | あつい (atsui) | あつかった (atsukatta) | あつくない (atsuku nai) | あつくなかった (atsuku nakatta) |
| na adjective | へんだ (hen da) | へんだった (hen datta) | へんではない (hen de wa nai) | へんではなかった (hen de wa nakatta) |
The de wa in the conjugation of the copula is often contracted in speech to ja.
Read more about this topic: Japanese Equivalents Of Adjectives