ain't的用法，不仅仅是am not

ain't主要用在非正式的口语中，它相当于am not, is not(isn't), are not(aren't), have not(haven't), has not(hasn't)。
I ain't traveling = I am not traveling.
我不去旅。
She ain't home. = She is not home.
她不在家。
He ain't doing his homework. = He is not doing his homework.
他没在做作业。
We ain't been there before. = have have not been there before.
我们以前从未去那儿。
She ain't been back yet. = She has not been back yet.
她还没回家。

ain't还有一些习惯用语：
Ain't that the truth?
Say it ain't so!
You ain't seen nothing yet.
If it ain't broke, don't fix it.

ain't还可用于反义疑句：
I'm drunk, ain't I? （也可用aren't I)
我醉了，是吗？

注意：ain't仅适用于非正式场合的口表达，它不用于正式场合或者书面语中。