ain't
/eɪnt/informal <非正式>
contraction
1- am not; are not; is not不是：
if it ain't broke, don't fix it.
要是没坏, 就不要修了。
ORIGIN: originally representing London dialect.
1.1
- has not; have not没有：
they ain't got nothing to say.
他们无话可说。
ORIGIN: from dialect hain't.
USAGE
The use of ain't was widespread in the 18th century, typically as a contraction for am not. It is still perfectly normal in many dialects and informal speech in both Britain and North America. Today, however, it does not form part of standard English and should never be used in formal or written contexts. See also usage at AREN'T.