In Japanese, there are two types of adjectives: “i-adjectives” (い形容詞) and “na-adjectives” (な形容詞). They have different conjugation rules, which are essential for forming negative and past tense sentences.
1. I-adjectives (い形容詞)
I-adjectives always end with the syllable “い”.
Conjugation Rules
Form | Rule | Usage | Example: 寒い (samui) – cold |
Present Affirmative | Use as is | To describe a present state | 今日は寒いです。 (Kyō wa samui desu.) – It’s cold today. |
Negative | Change the final “い” to “くない” (kunai) | To negate a state | 今日は寒くないです。 (Kyō wa samukunai desu.) – It’s not cold today. |
Past Affirmative | Change the final “い” to “かった” (katta) | To describe a past state | 昨日はとても寒かったです。 (Kinō wa totemo samukatta desu.) – It was very cold yesterday. |
Past Negative | Change the final “い” to “くなかった” (kunakatta) | To negate a past state | 昨日はそんなに寒くなかったです。 (Kinō wa sonna ni samukunakatta desu.) – It wasn’t that cold yesterday. |
Special Case:
The adjective いい (ii) – good is an exception. Its negative form is よくない (yokunai).
- いいです。 (ii desu.) – It’s good.
- よくないです。 (yokunai desu.) – It’s not good.
2. Na-adjectives (な形容詞)
Na-adjectives often don’t end with “い”. When they modify a noun, you need to add “な” after the adjective. When used alone, “な” is not needed.
Conjugation Rules
Form | Rule | Usage | Example: 静か (shizuka) – quiet |
Present Affirmative | Add “です” (desu) after the adjective | To describe a present state | この図書館は静かです。 (Kono toshokan wa shizuka desu.) – This library is quiet. |
Negative | Add “じゃありません” (ja arimasen) after the adjective | To negate a state | この図書館は静かじゃありません。 (Kono toshokan wa shizuka ja arimasen.) – This library is not quiet. |
Past Affirmative | Add “でした” (deshita) after the adjective | To describe a past state | 昨日の夜は静かでした。 (Kinō no yoru wa shizuka deshita.) – Last night was quiet. |
Past Negative | Add “じゃありませんでした” (ja arimasen deshita) after the adjective | To negate a past state | 昨日は静かじゃありませんでした。 (Kinō wa shizuka ja arimasen deshita.) – Yesterday was not quiet. |
Important Note:
When a na-adjective modifies a noun, you must add “な” between them.
- 静かな部屋 (shizuka na heya) – a quiet room
有名な歌手 (yūmei na kashu) – a famous singer
Thank you for the explanation! Now it’s clear. I thought な has to be used to introduce possession adjectives, but with your lesson it got clearer 🥰 I’m learning Japanese by myself since one year. I’m Italian but it’s easier to me learning it out from English ☺️
Thank you for the lovely message as well! I’m glad it was helpful to you!