文末表現N3
〜んじゃない
isn't it...? / don't... (casual)
Structure
句子（普通形）+ んじゃない
Explanation
Casual: ① contraction of のではないか, conjectural "isn't it...?"; ② prohibition "don't...". Distinguish by intonation.
Examples
もっと休んだほうがいいんじゃない？
Don't you think you should rest more?
遅刻するんじゃないよ。
Don't be late, OK?
Note
んじゃない in speech means conjecture or prohibition, distinguished by intonation.