1、第 1 页 共 3 页情态动词 can 的用法小结情态动词是高考的考点，对中学生来说也是个难点，而 can 的用法较其他情态动词多，现根据中学课本和近几年的高考试题，将其重点内容列出。一表示能力1Can you type?2I can do it.can 与 be able to 的区别1. be able to 能用于各种时态 。 “设法做成某事” 相当于 managed to do sth / succeeded in doing sth.。2. can / could 只能表示现在或过去的能力。例：1） A computer _ think for itself; it must be
2、told what to do.A. cant B. couldnt C. may not D. might not析：答案是 A，表示能力.2）. The fire spread through the hotel very quickly , but everyone _ get out.A. had to B. would C. could D. was able to析：答案是 D。表示经过努力才成功地逃出大火。二can/could 表示许可/允诺1Can/could Tom use the car?Yes , he can.与 may /might 的区别1might, could
3、比较委婉, 一般多用于疑问句.2在以 could, might 表示征询对方意见或表示请求时，回答应相应使用 can, may.例：1）. Could I borrow your dictionary? Yes, of course you _.A. might B. will C. can D. should析：答案是 C。第一句的请求用 could，所以回答时相应用 can2.） Might I watch TV after supper? Yes, you _.第 2 页 共 3 页A. may B. must C. might D. can析：答案是 A。第一句的请求用 might，所
4、以回答时相应用 may.3）.-Could I call you by your first name?-Yes, you _.A. will B. couldC. may D. might析：答案是 C。第一句的请求用 could，回答时相应用 can, 但选项中没有can，所以最佳的是 may.三can 指可能性He cant be at home. He has gone to Beijing.与 must may , might, could /Should, ought to 的区别1.should, ought to:按理应当, 很可能2.must：表示肯定的猜测3.may /mi
5、ght：表示可能的猜测4.can/could：表示否定或疑问的猜测例：1）-when can I come for the photo ? I need them tomorrow.- They _ be ready by 12:00A. can B .should C. might D. need析：答案是 B。根据情景，应表示可能的猜测，选 might 可能会走掉顾客2）Peter _ come with us tonight, but he isnt very sure yet.A. must B. mayC. can D. will析：答案是 B。根据 he isnt very sur
6、e，表示可能的猜测3）.Michael _ be a policeman, for he is much too short.A. neednt B. cant C. should D. may析：答案是 B. 根据 for he is much too short，可以判断是表示否定的猜测4）-_he be watching TV now? Yes, he _ be watching TV now. No, he _ be watching TV now.A. Must; can; mustnt B. Can; must; cantC. Can; can; mustnt D. May; mu
7、st; neednt析：答案是 B。第一句和第三句分别表示疑问和否定的猜测，第二句表示肯定的猜测。四. can /could have done第 3 页 共 3 页1 过去有能力做到而实际上没有做到的事情.含有责备或劝告之意。2 用于否定句,对过去发生事情的否定猜测.例：1）. -There were already five people in the car, but they managed to take me as well.-It _a comfortable journeyA. cant be B. shouldnt be C. mustnt have been D. couldnt have been 析： 答案是 D。根据上下文，已经有 5 个人在车上，但还是把我带上，所以，这次路途不可能是舒服的，属于否定的猜测。而第一句的时态用过去时，所以是对过去发生事情的否定猜测.2）You made a lot of mistakes in your composition yesterday. You _ it much better.A. can write B. could have writtenC. must have written D. should write析：答案是 B。意为：昨天你在作文里犯了很多错误，你本应有能力把它写得更好，含有责备的语气。
