Could I use your pen, please?
Can I ask you a question?
May we smoke here?
Could we visit you tonight?
Could I have some more cake?
May I borrow your book?
Can I see some identification?
I'm sorry. You can't. It doesn't work.
Yes, you can. Here's another piece.
Sorry, but I have to return it today.
I'm sorry, but I won't be home.
Of course. What do you need to know?
Certainly. I have my ID right here.
No, you can't. Please go outside.