Meaning
The speaker reminds the listener of something they consider obvious, or offers a guess and expects agreement: 言ったじゃないですか (I told you, didn't I).
Formation
- Plain verb or い-adjective + じゃないですか: 言ったじゃないですか
- Nouns and な-adjectives without だ: 休みじゃないですか; casual じゃない?, written ではないか
- A cautious guess: + んじゃないですか: 帰ったんじゃないですか; after a noun なんじゃないですか
When to use it
- Core use
- Isn't it …, didn't I say — seeking agreement
Example
だから言ったじゃないですか
I told you so, didn't I?
Important notes
- Pay attention to the word form before the construction and to the particles around it.
Common mistakes
- Do not translate the pattern word for word; first identify its function in the whole situation.