77. May and can 

Can expresses ability.

 • She can speak English. 

• He can play the piano. 

• Can you speak Hindi?

 Can is also used in the sense of may to give permission, though may is more correct. 

• You can take one of those books. OR You may take one of those books.

 • You can go now. OR You may go now. 

Nowadays, can is also being increasingly used to ask permission.

 • ‘Can I come in, Sir?’