Language Functions “CAN” performs! (Meanings of “CAN”)

• ability: Can you do this exercise? I can’t cook but I can drive.
• possibility, proposals: Can you meet at six? You can have coffee downstairs. She can’t make it to class today. / We can go to the beach, if you like.
• Please, do it (asking sb to do sth): Can you…? as in “Can you sign here? Can you open the door?”
• Requests: Can I have…, please?
• Permission & prohibition: Can you come? (= do you have permission; it can also be possibility), You can’t park here, We can go (they gave us permission).
• …

Compare with another language function: Offering yourself to do something for the rest.

• Shall I open the window? – You know it’s very hot and that people would like that.
• Can I open the window? – You don’t know what people feel, but you would like to open the window, so you ask them if it’s OK (permission).