情态动词专项练习1. Jean have kept his promise. I wonder why he changed his idea.A. mustB. shouldC. needD. would解析：选B. “should have +过去分词” 表示“过去本来应该(但没能)做某事”；keep one’s promise 意为“信守诺言”。
2. Jane have come to the party, but she not find the exact time.A. could; couldB. might; couldC. should; couldD. should; would解析：选A.“ could have+过去分词表示过去本来应该(但没能)做某事”。
3. So many mistakes in your homework! You more careful.A. may beB. had toC. would beD. should have been解析：选D. “You should have been more careful”. 意为：你本来应该更细心的。
4．Her brother be at home now, because he was seen playing basketball in the stadium just now.A. mustn’tB. needn’tC. can’tD. shouldn't解析：选C. can’t be at home 意为：不可能在家。
5．---I can’t understand wh y our boss is late.---He the early bus.A. could missB. may have missedC. can have missedD. might miss解析：选B. “may have+过去分词”表示对过去动作的判断，意为：可能做了某事。
注意：can表示可能时，只能用于疑问句和反问句。
6. She didn't answer the phone, she ______ asleep.A. may beB. must beC. should have beenD. must have been解析：选D. 表示：对过去发生的事情的肯定推测。
7．The little girl’s eyes were red. She ______.A. may cryB. must cryC. must be criedD. must have been crying解析：选D. 意为：她刚才肯定一直在哭。
对过去某事正发生的推测。
8．He______ his supper now, for the dining hall is still closed.A. can’t be havingB. needn’t be havingC. mustn’t be havingD. shouldn't be having解析：选A. 对现在正在发生的事情的否定推测。
9．I parked my bike behind the building, but now it is gone. It ________ .A. may be stolenB. must be stolenC. must have been stolenD. must have stolen解析：选C. 对过去发生的事情的肯定推测的被动式。
10. ______ Mr. Black_______go to work by ferry before the bridge was built?A. Did; used toB. Use; toC. Did; use toD. Does; use to解析：选C. used to do的疑问式，可以是Used+主语+to do ?或Did +主语+use to do?11. The hotel is only a stone’s throw away, you ______ take a bus.A. need not toB. not need toC. don't needD. need not解析：选D. 说话人认为不必要乘车, need 为情态动词。
12. I am busy now, _______ my brother do it for you ?A. WillB. ShallC. MustD. May解析：选B. 在疑问句中shall 用于第三人称，也表示征求意见。
13. ---You needn’t do it right now, need you?---Yes I am afraid I ______ .A. needB. needn’tC. mustD. mustn’t解析：选C. Yes的意思是：不。
意为：恐怕我必须现在就做。
14.My English-Chinese dictionary has disappeared . Who _____ have taken it?A. shouldB. mustC. couldD. would解析：选C. could/can have done 用于否定推测和疑问推测。
15. ---The room is so dirty._______ we clean it?----Of course.A．Will B. Shall C. Would D. Do解析：选B. shall 用在疑问句中，常用于第一，三人称，表示征求意见或请求指示。
16. If you have something important to do, you ______ waste any time.A. needn’tB. mustn’tC. may notD. won’t解析：选B. 根据句意用mustn’t17. If you want to borrow a football after school, your student card______ here.A. has to leaveB. must leaveC. has to be leftD. must be left解析：选C. have to 表示客观需要，must表示主观需要。
学生证必须放在此是客观需要。
18. “ Did you scold him for his carelessness?”“Yes, but _____ it”A. I’d rather not doB. I’d rather not have doneC. I shouldn’t doD. I’d better not do解析：选B. would rather 加完成时表示对完成了的或过去了的事情的态度。
意为：当时是不情愿做的。
19. “ Don’t get near to it . It is too dangerous!”“_______” .A. Yes, I won’tB. No, I don’tC. No, I can’tD. No, I won’t解析：选D. A为错误的表达方式；B和C没有直接回答对方的问候。
20. He must be in the classroom, _______ he?A. mustn’tB. can’tC. isn’tD.can解析：选C. 对表否定的must进行反意疑问时，要用句子的实义动词21. He________ be in the garden. He must be in the room.A. can’tB. mustn’tC. will notD. may not解析：选A. 否定推测用can’t不用mustn’t22. “Do you have to leave now?”“I am very sorry, but I really______.”A. can’tB. haveC. shouldD. must解析：选D. 回答have to 的疑问句用must作肯定回答。
23. “Let’s go to the library, shall we?”“_________?”A. No, I can’tB. Yes, I willC. Yes , thank youD. No, we’d better not解析：选D. A,B,C都不能回答shall we, 此处D的语气比较婉转客气。
24. “Can I take it away?”“ You ______ better not.”A. shouldB. couldC. wouldD. had解析：选D. had better 与不带to 的不定式构成谓语，可以变成疑问句：Hadn’t you better----25. You _______ have brought your camera. They all had theirs with them.A. couldn’tB. needn’tC. wouldn’tD. mustn’t解析：选B. 本来不必要做某事.26. See who is there!______it be May?A. MayB. MustC. CanD. Will解析：选C. 表推测时A，B都用作疑问句。
27. John______ be a basketball player. He is much too short.A. mayB. mustn’tC. can’tD. should解析：选C. 断然的不定推测用can’t28. The Chinese teacher looks so pale. She ______ be ill.A. mustB. mustn’tC. canD. need解析：选A. 表示有把握的肯定推测用must29. Something______to save our earth. Do you think so?A. can doB. must doC. has to doD. must be done解析：选D. “something must be done” 意为：必须采取措施。
30. Look at what you have done! You ______ be more careful.A. oughtB. canC. wouldD. should解析：选D. ought 后应用to31. — Has Li Lin started? He said he would join in the party.— He ______. He is a man of keeping his word.A. could have leftB. must have leftC. can’t comeD. won’t be coming解析：B。