1, Couldn't you do a favour and leave me alone?

2, Could you do a favour for me?

3, I want you to do a favour for me.

4, Who is Mary go to do a favour for?

5, I hope i can do a favour.

6, It's quite common, if someone agrees to do a favour, to use the future tense to promise a reward. So for example, you might say.

7, But he browbeats however: I will answer birthplace tomorrow, see you still can do a favour for who!