I already know all this! Now, you're just preaching to the choir.

这些我都知道！现在，你只是在" 白费口舌" 。

Sometimes a person fights a battle that has been decided or keeps arguing a question that has been settled. We say this is like " beating a dead horse."

有时，个人可能就经决定了的战而战斗，经解决了的问题。我们说，这简是白费口舌(就好象beating a dead horse)。

Still Matthew said nothing and Marilla had a sense of having wasted words and breath.

马修仍然言不发，玛丽拉有种白费口舌的感觉。

Save your breath, Gaby. It's not gonna happen.

别白费口舌了 加布 不可能的。

Don’t try to reason with Paul – you’re wasting your breath.

【waste】别跟保罗讲道理，你在白费口舌。

You're just shouting into the wind.

你只是在白费口舌。

Her good advice was wasted on the children.

【waste】她对孩子们的规劝是白费口舌了。

Save your breath. She’s already made up her mind.

【breath】别白费口舌了，她主意定。