do sb a favor

ask sb for help/a favor

Could you do me a favor?

Would you mind doing me a favor?

Would you mind helping me out?

Could I ask you for a favor?

Do you mind if I ask you for a favor?

Would you mind if I asked you for a favor?

I need to ask you for a favor.

I need to ask you to do me a favor.

I need to ask you for help.

Dialogues

A: Would you do me a favor?

你能幫我一下嗎？

B: Sure. What is it?

當然可以，什么事？

A: Could you give me a ride home tonight?

今晚能送我回家嗎？

B: Yeah. I guess. Don't you live kind of far away, though?

我想可以。不過，你是不是住的有點兒遠？

A: Would you mind picking up some things on your way home from work?

你能在下班回來的路上給我買點東西嗎？

B: Sure. As long as it doesn't take too long.

當然可以。只要不花太長時間就行。