Save your breath to cool your porridge.

不要费口舌了。

I feel like I’m just wasting my breath trying to explain things to him.

我觉得跟他解释简直是费唇舌。

Trying to sell overcoats in midsummer is a real mug's game.

大夏天推销大衣, 真是费气。

Mr. Taylor’s present behaviour stultifies his previous efforts.

泰勒先生目前的行为使他过去的努费了。

To argue with him is like beating the air.

和他辩论是费气。

I tried to chuff her up in vain.

我想让她高起来,但是费气。

Hurling his arms and legs about wildly, he kept afloat but wasted much effort.

他用胳膊和腿在水, 这样虽可以漂浮, 但却费了许多气。

In making that plea he will breathe in vain.

他做那种恳求是费口舌的。

Our labour will not be lost.

我们的努不会费。

Pam’s flogging a dead horse trying to organize the theatre trip. It’s quite obvious that nobody’s interested.

帕姆想组织剧团巡迴演出，无疑是费心机。很明显没有人感趣。

All my efforts were vain.

我的一切努都费了。