waste one’s breath

waste one’s breath 白费唇舌

【例句】

◆ Don't waste your breath trying to persuade them, they'll never listen。 别白费口舌去说服他们，他们是决不会听的。 

◆ It's no use talking to her. You'll only waste your breath. 跟她说是没有用的，你不过是白费口舌。