Listen and complete the conversation with the expressions in the box. Then practise it in pairs.
A. Is it OK
B. I'm afraid not
C. Certainly
D. can I
Lan: Mum (1) _____________________ go to my friend's birthday party this Saturday evening?
Lan's mother: (2)_____________________. Whose birthday is it?
Lan: It's Mai's birthday, Mum. (3) ________________ if I stay the night at her house after the party?
Lan's mother: Oh, (4)_________________. You must come back home before 10 p.m. We're going to visit your grandparents early on Sunday morning.
Lan: OK, Mum. I'll be home before 10 p.m. then.