Japanese Adjectives: I-Adjectives vs Na-Adjectives Explained

The short answer

い-adjectives end in い and change their ending: たかい → たかくない (not expensive).
な-adjectives need な before a noun: しずかなへや (a quiet room).
Japanese adjectives conjugate for negative and past, a bit like verbs.
Watch out: きれい and きらい end in い but are な-adjectives. いい (good) is irregular.

Two types of adjectives

	い-adjectives	な-adjectives
Ends in	い (always)	anything (no い needed)
Before a noun	たかいくるま (expensive car)	しずかなへや (quiet room)
Polite sentence	たかいです	しずかです
Examples	おおきい, ちいさい, おいしい	げんき, べんり, ゆうめい

い-adjectives

These end in い and go straight before a noun. Here are some of the most useful ones. Tap to hear them:

おおきいōkii
big
ちいさいchiisai
small
たかいtakai
expensive / tall
やすいyasui
cheap
あたらしいatarashii
new
ふるいfurui
old (things)
あついatsui
hot
さむいsamui
cold (weather)
おいしいoishii
delicious
たのしいtanoshii
fun
むずかしいmuzukashii
difficult
いいii
goodIrregular, see below.

Conjugating い-adjectives

Replace the final い with a new ending. The です stays the same:

Form	Pattern	Example	Meaning
Present	〜いです	たかいです	is expensive
Negative	〜くないです	たかくないです	isn’t expensive
Past	〜かったです	たかかったです	was expensive
Past negative	〜くなかったです	たかくなかったです	wasn’t expensive

な-adjectives

These behave more like nouns. They need な when they come before a noun, and use です / じゃない like nouns do:

しずかshizuka
quiet
にぎやかnigiyaka
lively, busy
きれいkirei
pretty / cleanEnds in い, but it’s a な-adjective!
げんきgenki
healthy, energetic
べんりbenri
convenient
ゆうめいyūmei
famous
すきsuki
liked
きらいkirai
dislikedAlso a な-adjective.
ひまhima
free (not busy)
たいへんtaihen
tough, hard (situation)

Conjugating な-adjectives

Form	Pattern	Example	Meaning
Present	〜です	しずかです	is quiet
Negative	〜じゃないです	しずかじゃないです	isn’t quiet
Past	〜でした	しずかでした	was quiet
Past negative	〜じゃなかったです	しずかじゃなかったです	wasn’t quiet

A slightly more formal negative is じゃありません: しずかじゃありません. Both are correct.

Before nouns: the key difference

おおきいいえōkii ie
a big houseい-adjective: straight before the noun.
きれいなはなkirei na hana
a pretty flowerな-adjective: add な.
ゆうめいなレストランyūmei na resutoran
a famous restaurant
あたらしいスマホatarashii sumaho
a new smartphone

Useful sentences

にほんごはむずかしいですが、たのしいですnihongo wa muzukashii desu ga, tanoshii desu
Japanese is difficult, but fun.
きょうはさむくないですkyō wa samukunai desu
It’s not cold today.
りょこうはたのしかったですryokō wa tanoshikatta desu
The trip was fun.
このへやはしずかじゃないですkono heya wa shizuka ja nai desu
This room isn’t quiet.

Notice that すき is a な-adjective, which is why it marks the liked thing with が: ねこがすきです. More in は vs. が.

Adjective check0/5

“It isn’t expensive.”
“A quiet room”:
“The trip was fun.” (たのしい)
Which is a な-adjective?
“It was good.” (いい)

Adjectives are everywhere in our guides on colours and food. Next up in grammar: the ます form of verbs.

Frequently asked questions

What is the difference between i-adjectives and na-adjectives?

い-adjectives end in い and change their ending to conjugate (たかい → たかくない). な-adjectives need な before a noun (しずかなへや) and conjugate like nouns with です and じゃない.

Is kirei an i-adjective?

No. きれい (pretty, clean) ends in い but is a な-adjective: きれいなはな, a pretty flower. The same applies to きらい (disliked) and ゆうめい (famous).

How do you make Japanese adjectives negative?

For い-adjectives, replace い with くない: たかい → たかくない. For な-adjectives, add じゃない: しずか → しずかじゃない. Add です for politeness.

Why is ii irregular?

いい (good) comes from the older form よい, which is used for its conjugations: よくない (not good) and よかった (was good).