Japanese Adjectives Complete Guide: i-Adjectives vs na-Adjectives

Two Types of Adjectives — One Key Difference

Japanese adjectives come in two types: い-adjectives (i-adjectives) and な-adjectives (na-adjectives). They conjugate differently, connect to nouns differently, and make different past-tense forms. Mastering both is essential for describing anything in Japanese.

Quick Identification Test

• い-adjective: ends in い in dictionary form: おもしろい、たかい、あたらしい
• な-adjective: doesn’t end in い (or ends in い but acts like な): しずか、きれい、べんり

Trap: きれい (beautiful) ends in い but is a na-adjective! These must be memorised.

I-Adjectives: Conjugation Table

Na-Adjectives: Conjugation Table

Common I-Adjectives

Common Na-Adjectives

Quick Drill

1. Past of おいしい?
2. Before a noun: しずか + まち (town)?
3. Is きれい an い or な adjective?

Answers: 1. おいしかった / 2. しずかなまち / 3. な-adjective (despite ending in い)

Yuka & Rei Sort Out い and な Adjectives

See how these words come alive in a real exchange between Yuka and Rei. Pay attention to how they explain — and occasionally correct — each other. That back-and-forth is exactly how language learning works.

Yuka

Rei, I keep making mistakes with adjectives. I wrote たべものはしずかです and my teacher marked it wrong. What happened?

Rei

しずか is a な-adjective, so in a sentence like that it becomes たべものはしずかではありません — but actually しずか means ‘quiet’ not ‘delicious’! You might mean たべものはおいしいです?

Yuka

Ha! Wrong word too! But how do I know which adjectives are い-type and which are な-type?

Rei

い-adjectives always end in い when they stand alone: おいしい、たかい、おもしろい. な-adjectives don’t end in い (or end in い but it’s a different kind): きれいな、しずかな、べんりな. When modifying a noun, い-adj stays the same; な-adj adds な.

Yuka

And for the negative past? That always trips me up.

Rei

い-adjective past negative: drop い, add くなかった. So おいしい → おいしくなかった. な-adjective: しずかではなかった. Practise these with common adjectives and they’ll become automatic.

5 Practice Sentences — Read These Aloud

Speak each sentence at least three times. Hearing your own voice say these words is the fastest route to natural recall.

1. このりょうりはとてもおいしいです。
   This food is very delicious. (い-adjective)
2. へやがきれいですね。
   Your room is beautiful/clean, isn’t it? (な-adjective)
3. きのうのえいがはあまりおもしろくなかったです。
   Yesterday’s movie wasn’t very interesting. (past negative)
4. このカバンはたかくておもいです。
   This bag is expensive and heavy. (two い-adj connected with くて)
5. しずかなまちにすみたいです。
   I want to live in a quiet town. (な-adj modifying noun)

Your Turn! Leave Your Sentence in the Comments

The best way to memorise vocabulary is to produce it yourself. Pick 2–3 words from this article and write your own sentences — about your daily life, your hometown, your work, anything.

Leave your sentences in the comments below. Other learners will read them, and you might inspire someone else’s learning journey. Log in to keep your comment history — our most active contributors appear in the Top Commenters ranking in the sidebar!

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