(x) May I go to the movie theater please?
No, you cannot / No, you can't
Can I play football with my friends?
Of course, you can. / Yes, you can.
Can I borrow you sneakers please?
Of course, you can. / Yes, you can.
(x) May they come your house tomorrow?
No, you cannot / No, you can't
(x) Can he ride a bicycle?
No, you cannot / No, you can't
May I sit next to you?
Of course, you can. / Yes, you can.