情态动词推测用法

　 情态动词的推测用法 一、 在肯定句中表示较有把握的推测用 must ， 意为“想必一定……” 1) 对目前状态的推测，用 must + be + 表语 a.

　--- Where is Mary?

　---She must be in the library. b. The story he told us must be true.

　 2)

　对目前动作的推测，用 must + 行为动词 a. She must know Beijing very well, for she has been there several times.

　3) 对正在发生事情的推测，用 must + be + v-ing

　a. He must be waiting for us at the school gate.

　4) 对已经发生或过去发生的事情的推测，用 must + have + p.p. a. She must have cried, for her eyes are still red.

　b. It must have rained last night, for the ground outside is wet.

　5)

　对已经发生并一直在持续的事情的推测，用 must + have + been + v-ing a. You look tired. You must have been working all day long.

　二、can (could) 作推测时，用法有如下 3 种：

　A) 在否定句中，表示有把握的否定推测，意为“不可能……” 1) 对目前状态的否定推测，用 can’t + be + 表语

　a. Don’t worry. The information can’t be true.

　 2) 对目前动作的否定推测 can’t + 动词 a. The boy is honest. He can’t tell lies.

　3) 对正在发生事情的否定推测，用 can’t + be + v-ing

　a. They can’t be watching TV, for the electricity has been cut off.

　4) 对已经发生或过去发生的事情的否定推测，用 can’t + have + p.p.

　a. She can’t have read that book, for she knows nothing about it. b. Jenny can’t have been with him at that time, for I was having dinner with her in my home. c. You can’t have seen him at the party last night. I saw him off at the airport yesterday afternoon.

　5 ）

　对已经发生并一直在持续的事情的否定推测，用 can’t + have + been + v-ing

　 a. They can’t have been practicing. You see, they haven’t made any progress. b. --- John walked straight into a wall. --- He couldn’t have been looking where he was going. B)

　在疑问句中，对事情的可能性提出疑问，表示“可能吗？会不会？” 1)

　表示对现在的推测，用 Can / Could + S + v. ?;

　a. --- Can it be true?

　--- No, it can’t be true.

　b. Where can they be now?

　2) 对过去的推测用 Can / Could + S + have + p.p. a. Can he have left yesterday?

　C)

　在肯定句中，表示 “有时候可能会”：

　a.

　It can be very cold here in winter. b.

　---Your daughter is well behaved.

　---Yes, but not always. Sometimes she can be very naughty.

　、 三、 在肯定句或否定句中，表示对用 事情把握不大的推测，用 may ( 或 might)。

　。

　might 比 may 表示的可能性更小，意为“可能……; 或许……” 1) 对目前动作的推测，用 may + 行为动词 a. He may get here anytime. b. Jack may not know this news.

　2) 对目前状态的推测，用 may + be + 表语 a. He may be at home.

　Let’s go and see.

　b. The story may not be true.

　 3) 对正在发生事情的推测，用 may + be + v-ing

　 a. They may be watching TV at home now. b. They may not be playing in the garden now.

　4) 对已经发生或过去发生的事情的推测，用 may + have + p.p. a. He may have heard of the news. b. It may (might) have rained during the night.

　c. She may not have learned English when she was at school.

　5) 对已经发生并一直在持续的事情的推测，用 may + have + been + v-ing a.

　The boy may have been playing computer games all the morning, for his eyes are red. b.

　How do they know we went out? They may have been watching us.

　 情态动词做推测用法的练习 1 --Look, it _____ be Mr. Wang.

　 –No, it _____ be him. He has gone abroad. a.

　may, mustn’t

　b.

　must, may not

　c.

　must, can’t

　d.

　can, may not 2 --Tom is never late for work. Why is he absent today?

　--Something ____ to him. a.

　must happen

　 b.

　should have happened

　 c.

　could have happened

　d.

　must have happened 3 --Do you know where David is? I couldn’t find him anywhere. --Well. He _____ have gone far—his coat’s still here. a.

　shouldn’t

　b.

　mustn’t

　c.

　can’t

　d.

　wouldn’t 4 Aunt Catherine _____ the train, otherwise she would have arrived here by now. a.

　must have missed

　b.

　should miss

　c.

　didn’t

　d.

　doesn’t 5 He must have seen the famous writer last night, _____ he? a.

　mustn’t

　b.

　hasn’t

　c.

　didn’t

　 d.

　doesn’t 6 --Mr. Smith must have lost his way, for he hadn’t arrived yet. --No, he _____ have lost his way. He has got a map with him. a.

　mustn’t

　b.

　should

　c.

　can’t

　 d.

　may 7 If there is a strike of bus drivers, they _____ walk to school tomorrow. a.

　must have

　b.

　had to

　c.

　may have

　d.

　may have to 8 He _____ have completed his work; otherwise he wouldn’t be enjoying himself by the seaside. a.

　should

　b.

　must

　c.

　wouldn’t

　d.

　can’t 9 Helen _____ go on the trip with us, but she isn’t quite sure yet. a.

　shall

　b.

　must

　c.

　may

　d.

　can 10 Mary _____ be in London because I saw her in town just now. a.

　mustn’t

　b.

　isn’t able to

　c.

　may not

　d.

　cannot 11 --There is no light in the room.

　--_____he be sleeping? a.

　Must

　b.

　Shall

　c.

　Can

　d.

　Will 12 It ____ he that tells such a lie; it ____ you.

　 a.

　must not be, must be

　b.

　can’t be, must be

　c.

　must not be, can be

　 d.

　can’t be, can be 13 All the students in Class 8 passed the physics exam. It _____ have been difficult. a.

　must

　 b.

　mustn’t

　c.

　shouldn’t

　 d.

　can’t 14 --I can’t get through to my office. --The line is busy. Someone _____ the telephone. a.

　must use

　b.

　must be using

　c.

　should use

　d.

　can be using 15 Lily _____ read the novel, for she knows nothing about it. a.

　can’t have

　b.

　mustn’t

　c.

　can’t

　d.

　mustn’t have 16 --Do you still remember that summer holiday when we went together to the summer palace? --I can’t remember it well. _____ it have been last winter holiday? a.

　Should

　b.

　May

　c.

　Must

　 d.

　Can 17 --There were already five people in the car but they managed to take me as well. --It _____ a comfortable journey. a.

　can’t be

　b.

　mustn’t have been

　 c.

　shouldn’t be

　d.

　couldn’t have been. 18 Peter _____ come with us tonight, but he is not sure yet. a.

　must

　b.

　may

　c.

　can

　d.

　will 19 Surely nothing _____ be going on there so late at night. a.

　need

　b.

　shall

　c.

　could

　d.

　must 20 This cake is very sweet. You _____ a lot of sugar in it. a.

　should put

　b.

　could have put

　c.

　might put

　d.

　must have put 21.

　My five-year-old boy left home three days ago. An idea that something _____ to him worries me a lot. a.

　might have happen

　b.

　should have happened c.

　must be happened

　 d.

　must have happened 22. Jack’s score is the highest in his department. He _____ have studied very hard. a.

　may

　 b.

　should

　c.

　must

　d.

　ought to

　Key:

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