to save one's breath
01
言っても無駄, 話しても仕方ない
to avoid wasting one's time and energy by not trying to persuade or convince someone who is unlikely to change their opinion or behavior
![to [save] {one's} breath definition and meaning](https://cdn.langeek.co/photo/40965/original/?type=jpeg "to [save] {one's} breath definition and meaning")
例
Save your breath, Tom. There's no way they'll agree to the deal.
彼女に忠告しようとしたけど、言うだけ無駄だった。
