Inglês & Portuguese como Segunda Língua

Expressar permissão / Expressing permission:

• • Can/May I open the window, please?
  • – Yes, of course you can/may or
  • - No, I’m sorry, you can’t/may not.
  • - You wanted to borrow my printer. OK, you can/may.
• • Could I look at your map, please?
  • – Yes, you can/may (could) or
  • - I’m sorry, but you can’t (couldn’t) park here.

fonte: http://www.teclasap.com.br/blog/2008/12/21/gramatica-modal-verbs-3-can-may-might-could/