adjective N5 essential casualpolitewritten
な-adjectives — 〜な / 〜だ describing words (present, negative, past)
な形容詞
Meaning
- descriptive words that behave like nouns — they borrow the copula (静か + です / だ) to make a sentence and add な before a noun
Unlike an い-adjective, a な-adjective has no conjugation of its own. It sits still and lets the copula do the work — です / だ for the present, でした / だった for the past — exactly as a noun would. The name comes from the な it needs before a noun.
Key sentence
この部屋は静かです。
This room is quiet.
Formation
| Attaches to | Form | Example |
|---|---|---|
| Present (polite) | stem + です | 静かです |
| Present (plain) | stem + だ | 静かだ |
| Negative | stem + じゃないです / ではありません | 静かじゃないです |
| Past | stem + でした / だった | 静かでした |
| Past negative | stem + じゃなかったです | 静かじゃなかったです |
| Before a noun | stem + な + noun | 静かな部屋 |
| Adverb | stem + に | 静かに (quietly) |
When: な-adjectives borrow the copula for tense and negation, so the endings are just です / だ・じゃない・でした. The plain だ-forms (静かだ, 静かだった) are the casual register introduced in the next unit; the polite です-forms above are enough to describe things now.
Examples
この町はとても静かです。
This town is very quiet.
present + polite です
駅前はあまり便利じゃないです。
The area by the station isn't very convenient.
negative じゃない + です
子どもの頃、この公園は有名でした。
When I was a child, this park was famous.
past でした
彼女はいつも元気な人です。
She is always an energetic person.
な before a noun
図書館では静かに歩く。
At the library, walk quietly.
adverb に modifying a verb
When you can't use it
- Never conjugate a な-adjective like an い-adjective: 'was quiet' is 静かだった / 静かでした, never ×静かかった. The traps 綺麗 and 嫌い end in い but are な-adjectives — 綺麗な花, 綺麗でした.
- Before a noun you must insert な (静かな町); dropping it (×静か町) is ungrammatical. This な is what names the class.
Easily confused with
い形容詞 い-adjectives change their own ending (高い → 高かった). な-adjectives keep one fixed shape, let the copula carry tense and negation, and need な before a noun. 〜で (な-adj) To link a な-adjective to another clause ('quiet and clean'), the copula's て-form で does it: 静かで、きれいだ. That connecting で is its own point. 〜になる To say something becomes quiet, a な-adjective takes に + なる (静かになる) — parallel to an い-adjective's 〜くなる (高くなる).
Notes
- A quick test: form the past. い-adjectives take 〜かった (高かった); な-adjectives take だった / でした (静かだった). This correctly sorts the traps 綺麗 and 嫌い, which end in い but are な-adjectives (綺麗だった, 嫌いでした).
See な形容詞 in real sentences
Jengo shows な形容詞 the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in Jengo