You (may/could) _________ leave now if you wish.

(Could/May) ______ you open the window a bit, please?

(May/Can) _____________ you play the piano?

Listen, please. You (may not/could not) ______________ speak during this exam.

You (can't/might not) _____________ smoke on the bus.

(Can't/May) _________________ I make a call on your mobile?

Do you know if Mark (can/may) ________________ sing?

(Can't/May) ________________ I sit here, please?

Caroline, your friends (can/could) ______________ stay the night if they want to. They're perfectly welcome.

(May/Could) ____________ you lend me 40 Euros til Monday?