3 sentences

1. 别对他浪费口舌。

   bié duì tā làng​fèi kǒu​shé.

   Don't waste your breath on him.

   Source: OpenSubtitles

2. 不要白费口舌和他争论了。

   bù​yào bái fèi kǒu​shé hé tā zhēng​lùn le.

   Don't waste your breath arguing with him.

   Source: AI Challenger 2017

3. 别白费口舌去劝他了。

   bié bái fèi kǒu​shé qù quàn tā le.

   Don't waste your breath trying to persuade him.

   Source: AI Challenger 2017