い-Adjectives (i-adj) — True Conjugating Adjectives
A distinct class of adjectives ending in the hiragana い. They behave more like verbs than nouns because they conjugate themselves for tense and negation without relying on the copula.
Structure
[い-Adj] + Noun | [い-Adj] + です
Examples
面白い映画を見ました。
Omoshiroi eiga o mimashita.
I watched an interesting movie.
面白い (interesting) directly modifies 映画 (movie), no particle needed
今日は寒くないです。
Kyou wa samukunai desu.
It is not cold today.
寒い → 寒くない (negative: drop い, add くない)
テストは難しかったです。
Tesuto wa muzukashikatta desu.
The test was difficult.
難しい → 難しかった (past: drop い, add かった)
• Conjugation: Keep the stem, swap the ending. Negative = くない, Past = かった, Past negative = くなかった. • Irregular いい: 'Good', いい (ii), is irregular because its stem is よい (yoi): 'not good' = よくない, 'was good' = よかった. • Modification: Never insert な or の when placing an い-adjective before a noun (面白い映画, not 面白いな映画).
Commonly confused with
The JLPT rarely asks whether you recognise a pattern — it asks which of several similar patterns fits. These are the ones い-Adjectives is tested against.
vs な-adjectives
い-adjectives conjugate themselves (寒い→寒くない→寒かった) and attach directly to nouns; な-adjectives don't conjugate — the copula does the work (元気だ→元気じゃない), and they need な before a noun (元気な人).
vs な-adjectives that end in い (綺麗, 嫌い)
A few な-adjectives end in the sound い (きれい, きらい) but are NOT い-adjectives: they take な (綺麗な人) and conjugate via the copula (綺麗じゃない), never 綺麗くない.
More adjectives
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