请人帮忙；谢人做事used when troubling somebody to do something ; used to thank somebody for taking the trouble to do something

• 请你偏劳吧，我实在脱不开身。

  I'm really tied up. Can I trouble you to do it please?

• 让你偏劳，实在于心不安。

  I am really embarrassed to trouble you so much.

• 谢谢你，多偏劳了。

  Thank you for all your trouble.