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JLPT N4 · Sentence patterns

じゃないか (janai ka)

～じゃないか — “isn't it?” / “let's ～, shall we?”

In short · じゃないか (casual; politely ではありませんか) has three common uses: pointing out something the speaker has just noticed (“it's ～, isn't it!”), asking for agreement, and, with the volitional form, inviting others (“let's ～”).
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Pattern

  • 普通形（名詞・な形容詞は だ を除く）＋ じゃないか いい天気じゃないか (Nice weather, isn't it!)
  • 動詞の意向形 ＋ じゃないか 行こうじゃないか (Let's go, shall we?)

Where it comes from

It is the casual form of ～ではないか. It looks like a negative question, but it does not really ask “isn't it?” Instead it calls the listener's attention (“look, it's ～”) or asks for agreement.

When to use it

For a remark or exclamation, as in いい天気じゃないか, the ending falls. After the volitional form, as in みんなで行こうじゃないか, it becomes a fairly strong call to your group: “let's do it.”

Things to watch

It sounds casual and rather masculine. With women or superiors, ～ではありませんか or ～でしょう is more natural. ～じゃない？ has a similar meaning and is used more widely.

Examples

  • みんなで一緒（いっしょ）に行（い）こうじゃないか。

    Minna de issho ni ikō janai ka.

    Let's all go together, shall we?

    Volitional form + じゃないか = a call to join in.

  • いい天気（てんき）じゃないか、散歩（さんぽ）に行（い）こう。

    Ii tenki janai ka, sanpo ni ikō.

    It's nice weather, isn't it—let's go for a walk.

  • もう少（すこ）し待（ま）ってみようじゃないか。

    Mō sukoshi matte miyō janai ka.

    Let's wait a little longer, shall we?

Common mistakes

  • It is not a real negative question. いい天気じゃないか means “what nice weather,” not “isn't the weather good?” as a question.
  • Do not use it with superiors. Politely, say ～ではありませんか or ～ましょう.

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