い形容詞
い-adjective conjugation
〜い → 〜くない／〜かった／〜くなかった
い-adjectives conjugate themselves: 高い → 高くない (not), 高かった (was), 高くなかった (wasn't).
この本は高くなかったです。
This book wasn't expensive.
10 forms, grouped and explained. Free, no account needed to read.
Japanese has two kinds of adjective and they behave differently. Everything below covers which is which and what you can do with each.
い-adjective conjugation
〜い → 〜くない／〜かった／〜くなかった
い-adjectives conjugate themselves: 高い → 高くない (not), 高かった (was), 高くなかった (wasn't).
この本は高くなかったです。
This book wasn't expensive.
な-adjective usage
〜な + N ／ 〜です・じゃありません
な-adjectives take な before a noun (静かな町) and conjugate with です like nouns.
ここは静かな町です。
This is a quiet town.
to become ...
い-adj(く) / な-adj・N(に) + なる
Expresses change of state: 寒くなる (get cold), 元気になる (get well), 先生になる (become a teacher).
最近寒くなりましたね。
It's gotten cold recently, hasn't it?
more than (comparison)
A は B より + adj
Marks the thing being compared against: "A is more ... than B".
電車はバスより速いです。
Trains are faster than buses.
the most (superlative)
N の中で + N が いちばん + adj
Expresses the superlative: among a group, X is the most ...
果物の中でりんごがいちばん好きです。
Among fruits, I like apples the most.
too much, excessively
V-masu stem / い-adj -い / な-adj + すぎる
Always negative — it marks a problem, not an intensity. 高すぎます means the price is a problem, unlike とても高い which is simply an observation.
いい becomes よすぎる, and ない becomes なさすぎる.
昨日は食べすぎました。
I ate too much yesterday.
not very / not much
あまり + negative
With a negative predicate, あまり means "not very" or "not often".
肉はあまり食べません。
I don't eat meat very often.
Confused with あまり vs ぜんぜん
not at all
ぜんぜん + negative
With a negative predicate, ぜんぜん means "not at all" — a complete negation.
お酒はぜんぜん飲みません。
I don't drink alcohol at all.
Confused with あまり vs ぜんぜん
easy to ~ / hard to ~
V-masu stem + やすい / にくい
A property of the thing, not of you. この本は読みやすい says the book is written clearly — it is not a comment on your reading ability.
Both behave as い-adjectives afterwards: 読みやすかった, 読みやすくない.
このペンは書きやすいです。
This pen writes nicely.
shows signs of feeling ~
い-adj -い / な-adj + がる
Japanese doesn't let you state another person's feelings flatly. 寒い is what *you* feel; for someone else you need 寒がっている — they are *acting* cold.
Same for 欲しい → 欲しがる, 嬉しい → 嬉しがる. Getting this wrong is one of the most audible learner mistakes.
子供が新しい自転車を欲しがっています。
My child wants a new bicycle.
Spaced repetition brings each form back right before you’d forget it, inside real sentences. Free, forever, no paywall.