短语 have a big mouth 用来形容一个说话声大、爱说闲话而且无法保守秘密的人。

例句

Jimmy has a big mouth. Yesterday I told him that I am leaving the company and today everybody knows about it.

I could never be a spy. I have a big mouth!

请注意

短语 all mouth 常会用在 'be all mouth and no trousers' 这个表达中，意思是只说不做。

I bet you haven't asked your boss about that pay rise you talk so much about; you are all mouth and no trousers!