A Guide To Japanese Adjectives: I-Adjectives And Na-Adjectives
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Japanese adjectives are divided into two distinct groups based on how they behave and conjugate.
You need to learn the rules for both i-adjectives and na-adjectives to describe things correctly.
These two types of adjectives have different endings and follow unique grammatical patterns.
I’ll explain exactly how to identify, use, and conjugate both types below.
Table of contents:
What are i-adjectives?
I-adjectives are descriptive words that always end with the hiragana character い (i).
They’re sometimes called “true adjectives” because they can act as verbs in a sentence.
You can place an i-adjective directly in front of a noun to describe it.
You can also place it at the very end of a sentence.
Here are a few common i-adjectives.
| Japanese | Romaji | English Meaning |
|---|---|---|
| 高い (たかい) | takai | high / expensive |
| 寒い (さむい) | samui | cold |
| 美味しい (おいしい) | oishii | delicious |
| 新しい (あたらしい) | atarashii | new |
Let’s look at an example of an i-adjective modifying a noun directly.
高い車を買いました。
Now let’s see an i-adjective placed at the end of a sentence.
この車は高いです。
How to conjugate i-adjectives
I-adjectives change their endings to show tense and polarity.
To conjugate them, you must drop the final い (i) and attach a new ending.
You then add the polite word desu to the end of the sentence.
Here’s the standard polite conjugation pattern for the word takai (expensive).
| Tense | Japanese | Romaji | Meaning |
|---|---|---|---|
| Present | 高いです | taka-i desu | is expensive |
| Negative | 高くないです | taka-kunai desu | is not expensive |
| Past | 高かったです | taka-katta desu | was expensive |
| Past Negative | 高くなかったです | taka-kunakatta desu | was not expensive |
The only major exception is the word ii (good).
It changes to its older form yoi before conjugating.
This means “not good” becomes yokunai desu instead of ikunai desu.
What are na-adjectives?
Na-adjectives function much more like nouns in Japanese grammar.
They require the hiragana character な (na) to connect directly to a noun.
Here are a few common na-adjectives.
| Japanese | Romaji | English Meaning |
|---|---|---|
| 静か (しずか) | shizuka | quiet |
| 元気 (げんき) | genki | healthy / energetic |
| 親切 (しんせつ) | shinsetsu | kind |
| 便利 (べんり) | benri | convenient |
When a na-adjective is placed directly before a noun, the な (na) acts as a bridge.
彼は静かな人です。
If the na-adjective is placed at the end of a sentence, you drop the な (na).
Instead, you simply finish the sentence with the copula desu.
この部屋は静かです。
How to conjugate na-adjectives
Na-adjectives don’t change their own endings.
Instead, you conjugate the word desu that comes after them.
Here’s the polite conjugation pattern for the word shizuka (quiet).
| Tense | Japanese | Romaji | Meaning |
|---|---|---|---|
| Present | 静かです | shizuka desu | is quiet |
| Negative | 静かじゃありません | shizuka ja arimasen | is not quiet |
| Past | 静かでした | shizuka deshita | was quiet |
| Past Negative | 静かじゃありませんでした | shizuka ja arimasendeshita | was not quiet |
This makes na-adjectives very easy to conjugate once you know your basic noun endings.
公園は静かじゃありませんでした。
Tricky exceptions to watch out for
A few na-adjectives look exactly like i-adjectives.
Words ending in an “i” sound or the hiragana い (i) can sometimes be deceptive.
You must memorize these exceptions to avoid making conjugation mistakes.
Here are the most common na-adjectives that look like i-adjectives.
| Japanese | Romaji | English Meaning |
|---|---|---|
| きれい | kirei | beautiful / clean |
| 有名 (ゆうめい) | yuumei | famous |
| 嫌い (きらい) | kirai | disliked / hate |
| 得意 (とくい) | tokui | good at / skilled |
Even though kirei ends in an “i” sound, you must use the na-adjective rules.
きれいな花を見ました。
部屋はきれいじゃありませんでした。
