Modals of permission

Which modal is more formal to ask for permission?

• Can

• May

• Could

• Should

"Could" is often used to politely ask for permission.

• True

• False

"_________ I leave early today, please?"

Which sentences are correct?

• Can I borrow your pen?

• May you open the door?

• Could I have some water, please?

• May I go to the restroom?

_________ I borrow your book for a moment?

_________ I leave the classroom now?" (formal request)

_________ I use your phone for a second?" (informal)

"_________ you open the window, please?" (polite request)