じゃありません => not to be N5
Emphasize negative meaning
んじゃ => If ... then... N4
Condition (hypothetical condition)
じゃありませんでした => was not, were not N5
Emphasize negative meaning
そうじゃありません => Not like that, Not that way N5
Confirm
じゃないが => It's not that... but... N4
How to say the beginning
じゃ(あ) / では => Then, so (Expressing attitude) N5
Change the way you speak
んじゃない => can not, impossible to... N4
Ban
なけりゃ => If not ... N2
Condition (hypothetical condition)
じゃないか => right? isn't it? let's~; confirmation N4
Speculation
じゃ(あ) / では => then; well; so; well then N5
Change the way you speak
んじゃなかったか => shouldn't have... N4
Regret
んじゃないか => right? isn't it? let's~; confirmation N4
Confirm