Notes:Only i adjectives can be conjugated; na adjectives are treated as nouns
Adjectives and verbs conjugate similarly, except in masu tai
The Japanese customarily conjugate the adjective, not the verb. Example: omoshirokatta desu rather than omoshiroi deshita, and so forth
The desu / deshoo forms are actually conjugating desu, not the adjective.
| Romaji | Kana | ( Approximate )Meaning |
|---|---|---|
| omoshiro(i) [ desu / desho ] | おもしろ（い）（でしょう） | [ it is ] interesting |
| omoshiro(ku) | おもしろ（く） | adverb, also combining form |
| omoshiroku~nai [ desu / desho ] | おもしろくない | [ it is not ] interesting |
| omoshiro~katta [ desu / desho] | おもしろかった | [ it was ] interesting |
| omoshiroku~nakatta [ desu / desho] | おもしろくなかった | [ it was not ] interesting |
| omoshiro(i) desho | おもしろいでしょう | [ it is probably or will be ] interesting |