精选优质文档-倾情为你奉上1. can/could能力 He can sing songs in French. He could swim at the age of 3. 表示请求Can you help me carry the box into the room? Could you help me, please? 可能性， 表示有时会Jeff is clever, but sometimes he is very dull. 针对不同时间表示推测（只能用于否定句和问句）cant doHe cant be at home right now, for I saw him go out just now. cant be doingHe cant be studying in the classroom, for I saw him go to the football field with a football. cant have doneHe cant have finished h
