In Japanese, descriptive words split into two families: い-adjectives and な-adjectives (also called な-adjective verbs or na-adjectives). They serve the same purpose — describing nouns and making statements — but they connect to words in completely different ways. This is the most important new word class at the N5 level.
How to Tell Them Apart
The simplest method: look at the ending.
| Type | Ending | Examples |
|---|---|---|
| い-adjective | Ends in い | 暑い, 大きい, 面白い |
| な-adjective | Does not end in い (adds な before nouns) | きれいな, 静かな, 有名な |
Watch out for a major trap: きれい looks like it ends in い, but it's a な-adjective! Its kanji is 綺麗 — the い is just part of the reading, not an adjective ending. You must say きれいな部屋, never きれい部屋.
Function 1: Modifying Nouns (Before the Noun)
Both types can go before nouns to describe them, but they connect differently:
い-adjectives: Connect directly
The い ending itself functions like "___" (no extra word needed):
| English | Japanese | Note |
|---|---|---|
| Hot summer | 暑い夏 | い connects directly |
| Big room | 大きい部屋 | い connects directly |
| Interesting sport | 面白いスポーツ | い connects directly |
Common mistake: おおきのへや ← Wrong! い-adjectives already contain the connecting function. Don't add の.
な-adjectives: Add な before the noun
な-adjectives need な to connect to a noun:
| English | Japanese | Note |
|---|---|---|
| Quiet room | 静かな部屋 | な = connector |
| Famous country | 有名な国 | な = connector |
| Beautiful person | きれいな人 | な = connector |
Compare with "my room": 私の部屋 — here の connects two nouns. Because 私 (I) is a noun, the connector between nouns is の.
Summary of the three connectors:
| Source | Japanese connector | Example |
|---|---|---|
| い-adjective | い (built-in) | 暑い夏 |
| な-adjective | な | 静かな部屋 |
| Noun | の | 私の部屋 |
Function 2: As a Predicate (End of Sentence)
Both types can go at the end of a sentence to describe the topic. In this position, both add です:
い-adjective + です
夏は暑いです。 → Summer is hot.
| English | Japanese |
|---|---|
| Summer is hot. | 夏は暑いです。 |
| The room is big. | 部屋は大きいです。 |
| This movie is interesting. | この映画は面白いです。 |
な-adjective + です
Note: in predicate position, な disappears — just add です directly:
部屋は静かです。 → The room is quiet.
| English | Japanese |
|---|---|
| The room is quiet. | 部屋は静かです。 |
| The country is famous. | 国は有名です。 |
| This person is beautiful. | この人はきれいです。 |
Modification vs Predicate: Same Word, Two Positions
One table to see the difference:
| Type | Modifying a noun (before) | As predicate (after) |
|---|---|---|
| い-adjective | 暑い夏 | 夏は暑いです |
| な-adjective | 静かな部屋 | 部屋は静かです |
Key difference:
- い-adjectives keep い in both positions
- な-adjectives have な before nouns, but な vanishes at the end of a sentence (replaced by です)
N5 Essential Adjective Vocabulary
い-adjectives (memorize in pairs!)
| Japanese | Reading | Meaning | Opposite |
|---|---|---|---|
| 大きい | おおきい | Big | 小さい |
| 小さい | ちいさい | Small | 大きい |
| 新しい | あたらしい | New | 古い |
| 古い | ふるい | Old (things) | 新しい |
| 暑い | あつい | Hot (weather) | 寒い |
| 寒い | さむい | Cold (weather) | 暑い |
| 暖かい | あたたかい | Warm | 涼しい |
| 涼しい | すずしい | Cool | 暖かい |
| 高い | たかい | Expensive / Tall | 安い / 低い |
| 安い | やすい | Cheap | 高い |
| 面白い | おもしろい | Interesting / Fun | つまらない |
| 難しい | むずかしい | Difficult | 易しい |
| 易しい | やさしい | Easy | 難しい |
| 多い | おおい | Many | 少ない |
| 少ない | すくない | Few | 多い |
| 早い | はやい | Fast / Early | 遅い |
| 遅い | おそい | Slow / Late | 早い |
| 楽しい | たのしい | Fun / Enjoyable | — |
| 冷たい | つめたい | Cold (to touch) | — |
| 赤い | あかい | Red | — |
| 白い | しろい | White | 黒い |
| 黒い | くろい | Black | 白い |
| 青い | あおい | Blue | — |
| 若い | わかい | Young | — |
面白い doesn't just mean "interesting" — it also means "entertaining" or "good" for movies, books, and shows: この映画は面白いです (This movie is great).
な-adjectives
| Japanese | Reading | Meaning |
|---|---|---|
| きれい | きれい | Beautiful / Clean |
| ハンサム | ハンサム | Handsome |
| 親切 | しんせつ | Kind |
| 有名 | ゆうめい | Famous |
| 元気 | げんき | Energetic / Well |
| 静か | しずか | Quiet |
| にぎやか | にぎやか | Lively / Bustling |
| 暇 | ひま | Free (not busy) |
静か can only describe places and environments (the room is quiet, this area is quiet) — not people. To say "a quiet person," Japanese uses 無口な人 (a person of few words).
Summary
- Japanese adjectives split into い-adjectives and な-adjectives
- Modifying nouns: い-adjectives connect directly (暑い夏), な-adjectives add な (静かな部屋)
- As predicates: both add です (暑いです / 静かです)
- い-adjectives have a built-in connector — never add の after them
- きれい is a な-adjective despite looking like an い-adjective (biggest trap!)
- Memorize in pairs for double efficiency: big ↔ small, new ↔ old, hot ↔ cold, expensive ↔ cheap
Self-Check
Q1. Say "a famous university" in Japanese. (famous = 有名, な-adjective; university = 大学)
Show answer
有名な大学
有名 is a な-adjective, so it needs な before a noun. Never say 有名大学 or 有名の大学.
Q2. Which Japanese sentence is correct? A. きれい部屋 B. きれいな部屋 C. きれいの部屋
Show answer
B. きれいな部屋 is correct.
きれい is a な-adjective (even though it looks like it ends in い), so it needs な before a noun. A is missing な, and C uses の (which only goes between nouns).
Q3. Translate: "This movie is interesting, but it's long." (long = 長い)
Show answer
この映画は面白いですが、長いです。
面白い (interesting) + です + が (but) + 長い (long) + です. が is a conjunction meaning "but."