Japanese Adjectives: い-adjectives vs な-adjectives

Japanese adjectives come in two types, and they conjugate differently. Getting this right makes your Japanese sound natural.

い-adjectives

These end in い: 高い (expensive), 楽しい (fun), 新しい (new). They change form themselves — past tense is 〜かった (楽しかった = was fun), negative is 〜くない (高くない = not expensive).

な-adjectives

These need な when placed before a noun: 静かな部屋 (a quiet room), きれいな花 (a pretty flower). They behave more like nouns and use です/でした to change tense.

The tricky exceptions

きれい (pretty) and 嫌い (dislike) end in い but are actually な-adjectives. Memorise them so you don''t conjugate them like い-adjectives.

Quick rule

If it ends in い and is a native adjective, conjugate the adjective itself. If it needs な before a noun, treat it like a noun with です. Practise with real sentences and the pattern sticks fast.