じゃない

じゃない is the informal negative form of the copula だ, meaning "is not" or "isn't." It is the contracted form of ではない. Beyond simple negation, じゃない has several other important uses depending on intonation and context.

Negation: "is not"

The most basic use of じゃない is to negate nouns and な-adjectives in casual speech.

The polite equivalents are じゃないです (casual-polite) and じゃありません or ではありません (formal-polite).

Seeking confirmation: "isn't it?" / "right?"

With rising intonation (じゃない？), it functions like a tag question, asking the listener to confirm something.

Expressing surprise or realization

With falling intonation, じゃない can express pleasant surprise upon recognizing or realizing something – effectively meaning "Oh, it IS...!" despite its literally negative form. This usage is especially common among female speakers.

Softly suggesting or expressing an opinion

じゃない can also gently offer an opinion or suggestion, similar to "I think it's…" or "isn't it probably…?" This is common with いい to express casual approval.

Related forms

• じゃなかった: Past tense ("was not").
• じゃなくて: Connective form ("is not … but rather …").
• ではない: More formal written equivalent.