What does it mean word for word?
The phrase is a contraction of de wa nai, where ja is a colloquial form of de wa.
Which one should you use?
じゃない is the colloquial version, while ではない is its more formal counterpart. The form ではないです is used to provide a polite negation that is softer than the very formal ではありません.
Is there a formal and an informal way to say it?
じゃない is an informal expression primarily used in casual, spoken conversation. For a polite tone, you can use ではないです. The most formal way to say "it is not" is ではありません. The form ちゃう is a very casual and colloquial way to express the same idea.
How does it change in a sentence?
In casual speech, you can turn the statement じゃない into a question, such as "Is it not?", by using a rising intonation at the end. You can also make the informal じゃない polite by adding です to the end, creating じゃないです.
How do you pronounce it?
ja nai
Did you know?
- In some dialects, such as the Kansai dialect spoken in Osaka, you might hear ちゃう or ちゃうん instead of the standard じゃない to mean 'it is not'.
- Using じゃない to negate a noun is straightforward, but it cannot be used to negate 'i-adjectives' like 'samui' (cold), which require an entirely different conjugation pattern.
- While じゃない typically means 'it is not', when spoken with a specific rising intonation, it functions as a tag question to seek agreement, much like the English 'right?' or 'isn't it?'
Examples in context
- 遊びじゃないんだ。It is not a game.The sentence is useful for saying that something is not a game using じゃない.Tatoeba #2907532 by tommy_san, translation #9419410 by shekitten
- それ、私んじゃない。It is not mine.The sentence is useful for saying something is not mine using じゃない.Tatoeba #10759909 by small_snow, translation #7808143 by sharris123
- 本当で、冗談なんかじゃないよ。It is true, it is not a joke.The sentence is useful for stating that something is not a joke using じゃない.Tatoeba #11512733 by small_snow, translation #11512729 by Aghanim
- 彼は学生ではありません。He is not a student.
- このレポートは完成していません。This report is not complete.
- 彼女は先生ではないです。She is not a teacher.
- その情報は正確ではないです。That information is not accurate.
Example conversation
Misaki and Kenta are looking at a piece of clothing in a shop.
- 美咲 Misakiこれ、健太のシャツじゃない？Kore, Kenta no shatsu janai?Isn't this your shirt, Kenta?
- 健太 Kentaいや、僕のじゃないよ。Iya, boku no janai yo.No, it's not mine.
- 美咲 Misaki本当？デザインが似てるね。Hontou? Dezain ga niteru ne.Really? The design is similar.
- 健太 Kentaそうだね。でも僕のじゃない。Sou da ne. Demo boku no janai.That's true. But it's not mine.
Sources
- Pronunciation: Wiktionary entry じゃない, CC BY-SA 4.0, dump of 2026-09-26.
- Example sentences: Tatoeba CC BY 2.0 FR.
