Adjectives - Groups
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In Japanese, adjectives serve the same function as in English: they describe nouns. However, their grammar and conjugation work differently.
There are three main types of adjectives:
Each type has its own set of conjugation rules, which we will explore in this lesson.
These adjectives always end in「い」 in their dictionary form and directly modify nouns. They conjugate like verbs, changing form to indicate tense and polarity.
| Form | Suffix | Rule | Example: たかい | Romaji |
|---|---|---|---|---|
| Present Affirmative | - | Root + い | たかい | takai |
| Present Negative | kunai | Drop い, add くない | たかくない | takakunai |
| Past Affirmative | katta | Drop い, add かった | たかかった | takakatta |
| Past Negative | kunakatta | Drop い, add くなかった | たかくなかった | takakunakatta |
| Adverbial Form | ku | Drop い, add く | たかく | takaku |
| Te-form | kute | Drop い, add くて | たかくて | takakute |
この山は高いです。
Kono yama wa takai desu → This mountain is tall.
この山は高くないです。
Kono yama wa takakunai desu → This mountain is not tall.
昨日のテストは難しかったです。
Kinou no tesuto wa muzukashikatta desu) → Yesterday’s test was difficult.
彼の話し方は優しくて、聞きやすい。
Kare no hanashikata wa yasashikute → His way of speaking is gentle and easy to listen to.
Unlike -i adjectives, -na adjectives behave more like nouns and require な when modifying a noun.
| Form | Suffix | Rule | Example: きれい | Romaji |
|---|---|---|---|---|
| Present Affirmative | da / desu | Add だ (casual) / です (polite) | きれいだ / きれいです | kireida / kirei desu |
| Present Negative | janai | Add じゃない | きれいじゃない | kireijanai |
| Past Affirmative | datta | Add だった | きれいだった | kireidatta |
| Past Negative | janaikatta | Add じゃなかった | きれいじゃなかった | kireijanaikatta |
| Adverbial Form | ni | Add に | きれいに | kireini |
| Te-form | de | Add で | きれいで | kireide |
この部屋はきれいです。
Kono heya wa kirei desu → This room is clean.
この部屋はきれいじゃないです。
Kono heya wa kirei janai desu → This room is not clean.
彼女の声は静かで、落ち着く。
Kanojo no koe wa shizukade, ochitsuku → Her voice is quiet and calming.
静かに話してください。
Shizuka ni hanashite kudasai → Please speak quietly.
Despite ending in い, きれい (kirei), きらい (kirai) and ゆうめい (yūmei) are conjugated like な adjectives
There are two major irregular adjectives in Japanese:
| Form | Conjugation |
|---|---|
| Present Affirmative | いい / よい |
| Present Negative | よくない |
| Past Affirmative | よかった |
| Past Negative | よくなかった |
Although it looks like an -i adjective, it follows the よい conjugation rules.
い adjectives directly attach to nouns:
面白い映画
Omoshiroi eiga – An interesting movie
な adjectives require な before a noun:
静かな町
Shizukana michi – A quiet town
In informal speech, adjectives can end a sentence without needing です.
このラーメンは美味しい！
This ramen is delicious!
この問題は簡単。
This problem is easy.