The following modal verbs can be used to give or ask for permission.
•May is a polite modal verb used to ask for permission.
👉 May I use a calculator on the test? Yes, you may.
👉 May I have another piece of cake? No, you may not.
•Could is also used to ask for permission. It is less formal than using may.
👉 Could I have some more juice?
👉 Could I bring a friend to the party?
•Can is the least formal of the modal verbs used to ask permission.
👉 Can I play music?
👉 Can I wear shorts?