do someone a favor
US /duː ˈsʌm.wʌn ə ˈfeɪ.vər/
UK /duː ˈsʌm.wʌn ə ˈfeɪ.vər/

1.
帮一个忙, 施恩
to do something to help someone
:
•
Could you do me a favor and pick up my mail?
你能帮我一个忙去取我的邮件吗?
•
I'll do you a favor this time, but don't expect it again.
这次我帮你一个忙,但别指望下次。