高考研究英语中常用的情态动词主要有can，could，may，might，must，will，would，shall，should，ought to，dare，need，used to，had better等。在学习情态动词时应注意以下几点：同一情态动词表示不同的意义的情况；情态动词后跟各种形式的用法；尤其要注意＂情态动词+完成式＂是高考中的重点所在。
考向一 can，could与be able to的用法
☞Many people can use the computer.
☞If you have a good sleep，you will be able to work out this problem.
☞I could have worked out the problem，but I was too nervous.
☞How can you treat me like that?
☞Can I have a word with you? It won’t take long.(表示请求)我可以和你谈谈吗？不会花很多时间的。
(2018·北京卷·单项填空)In today’s information age, the loss of data _________ cause serious problems for a company.
A.need B. should C. can D. must
2.(2017·北京卷·单项填空)Samuel, the tallest boy in our class, ________ easily reach the books on the top shelf.
☞—May I play basketball this afternoon?
2．＂may/might as well＋动词原形＂意为＂最好，倒不如＂，may/ might well＋动词原形，意为＂很可能＂。
☞He may/ might well stay in Beijing now.
☞If you think the price of beef is too high，you might as well buy some pork.It depends on you.
You feel all the training a waste of time, but I’m a hundred percent sure later you’ll be grateful you did it.
A.should B. need C. shall D. may
☞You mustn’t play with the knife，or you may hurt yourself.你千万不要玩刀，否则会伤到自己。
☞Progress must lead to a better life and a better way of doing things.
☞If you must go，at least wait until the storm is over.
You needn’t come here this afternoon. 你今天下午不必来。
You don’t need to go now. 你不必现在就走。
I need to have a rest. 我需要休息一下。
Do we need to finish all the work today? 我们今天需要完成所有的工作吗？
1.—Can’t you stay a little longer?
—It’s getting late. I really _________go now, My daughter is home alone.
A .may B .can C . must D .dare
2.You __________be careful with the camera. It costs!
A .must B. may C. can D. will
【答案解析】考查情态动词。根据下文的it costs可知，照相机很昂贵，可推断此处是说，你一定要非常小心对待照相机。故选A 。may可能；can能够，有时会；will会，愿意。
☞Would you mind opening the window for me?
☞I will never talk to him again.
Fish will die without water.没有水，鱼会死去。
1.(2018·新课标II卷·短文改错)As kid, I loved to watch cartoons, but no matter how many times I asked to them, my parents would not to let me.
考向五 shall，should与ought to的用法
☞Shall we begin our new lesson today?
☞You shall be punished for what you have done.
☞You should be strict with yourself as an officer.
☞You ought not to be late for such an important meeting.
Whoever drives through a red light shall be fined at least 200 yuan.不论谁驾车闯红灯，罚款至少200元。
☞As we all know，an experienced teacher can make mistakes.
☞He can’t have left. His coat is here.
☞Mr Bush is on time for everything. How can it be that he was late for the meeting？布什先生做什么事情都很准时，他怎么可能开会迟到呢？
☞—What are you doing this Saturday?
—I’m not sure，but I might go to the Rolling Stones concert.
☞Someone must have used my umbrella yesterday. I found it wet.
☞There shouldn’t be any difficulty about passing the road test since you have practiced a lot in the driving school.
考向七 ＂情态动词＋have done＂的用法
1.＂must have done＂
☞It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的。
☞You must have been mad to speak to the servant. 你和仆人说话，一定是发疯了。
2.＂can’t have done＂
☞Mr Smith can’t have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。
☞Mary can’t have stolen your money. She has gone home. 玛丽不可能偷你的钱，她回家去了。
3.＂can have done＂
☞There is no light in the room. Can they have gone out? 屋里没有灯，他们可能出去了吗？
☞There is nowhere to find them. Where can they have gone? 到处找不到他们，他们可能到什么地方去呢？
4.＂could have done＂
☞He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。
5.＂may have done＂
☞—What has happened to George? 乔治发生了什么事？
—I don’t know. He may have got lost. 我不知道，他可能迷路了。
6.＂might have done＂
☞She might have achieved greater progress, if you had given her more chances. 如果你多给她点机会，她可能已经取得了更大的成绩。
7.＂would have done＂
☞I would have told you all about the boy’s story, but you didn’t ask me. 我本来会告诉你这个小男孩的故事，但是你没有问我。
8.＂should have done＂
☞Tom, you are too lazy. The work should have been finished yesterday. 汤姆，你太懒惰了，这项工作本来应该昨天就做完的。
☞Look, Tom is crying. I shouldn’t have been so harsh on him. 看，汤姆哭了，我本不应该对他如此严厉的。
9.＂ought to have done＂
表示过去应该做而实际并没有做，译成＂理应做……＂，往往表示遗憾。与＂should have done＂用法基本一样。
☞I ought to have gone home last Sunday. 我理应上星期日回家。
☞You ought not to have given him more help. 你不应该帮助他那么多。
10.＂need have done＂
表示本来需要做某事而实际没有做。＂needn’t have done＂则表示＂本来不需要做某事而实际做了＂
☞I needn’t have bought so much wine — only five people came. 我本来没有必要买这么多酒，只来了五个人。
☞He need have hurried to the station. In that case, he wouldn’t have missed the train. 他本来需要快点去车站的，那样的话，他就不会误了火车。
（2015·福建卷·单项填空）—Sorry, Mum! I failed the job interview again.
—Oh, it’s too bad. You _____________ have made full preparations.
A.must B. can
C.would D. should
1.Can you help me? I _________ never understand this.
2.___________ you tell me what time it is, please?
3.Henry ________ walk when he was one year old.
4.We are going for a walk. _________ you like to join us?
5.Tom, you ___________ leave your clothes on the floor like this.
6.The road is wet. It __________ have rained last night.
7.He has waited outside for half an hour. ___________ he come in?
8.These flowers have died. You _____________ have watered them.
9.__________ she be ten years old next month?
10.I ___________ have hurt your feelings but it was not my intention.
1.You _____________ give me a lift. I want to walk home for exercise.
A.needn’t B.couldn’t C.can’t D.mustn’t
2.Remember that in some countries, you _____________ take flowers of a certain colour, because they’re unlucky.
A.could not B.needn’t C.may not D.mustn’t
3.—Being young generations in China, _____________ they take up all of the challenges and opportunities that this country offers?
A.mustn’t B.mightn’t C. shouldn’t D. couldn’t
4.—_____________ you interrupt now? Can’t you see I’m on the phone?
—Sorry, sir, but it’s an emergency.
A.Can B.Should C. Must D. Would
5.It is said that people _____________ reduce the risk of catching some serious diseases by exercising.
A.must B.can C. would D. need
6.I was very surprised that that little child _____________ have said such rude words to his parents.
A.might B.could C. would D. should
7.My phone _____________ have been stolen while I was taking a bus. I can’t find it anywhere.
A.can B.must C.should D.would
8.You _____________ so much cash with you, you know —that shop accepted checks.
A.couldn’t have taken B.wouldn’t have taken
C.shouldn’t have taken D.needn’t have taken
9.Without your help, we _____________ our task on time. I cannot thank you enough.
A.can’t finish B.couldn’t finish
C.can’t have finished D.couldn’t have finished
10.—Bob didn’t pass this exam.
—What a pity! He _____________.
A.should study hard B.should have studied hard
C.would have studied hard D.could have studied hard
Miss Fang couldn’t read for very long without getting a headache. Her mother told her that she __1__go to the Health Service and see a doctor.＂You should see a doctor as soon as possible，＂ she said.＂You __2__need glasses.＂
When Miss Fang had free time, she went to the Health Service. The appointment clerk said that the doctor __3__see her at 3：30.
Miss Fang replied that she would not be able to be there at 3：30 because she had a class then.＂The doctor __4__take you at about ten to four，＂ the appointment clerk suggested.
＂__5__I put you down for ten to four，or would you rather come tomorrow？＂
Miss Fang thought she __6__(not) waste any more time. The teacher shouldn’t be unhappy if she asked for permission to leave the class a little early, as he was always so kind to everyone. And she replied, ＂I think I __7__make it at ten to four.＂
Miss Fang went to the class. She asked her teacher, ＂__8__I leave at 3：45 today？I __9__have an eye examination.＂ As expected, the teacher said, ＂Yes, of course you __10__.＂
1.(2017·天津) My room is a mess, but I ________clean it before I go out tonight. I can do it in the morning.
2.(2016·天津)It was really annoying; I ________ get access to the data bank you had recommended.
A.wouldn’t B. couldn’t
C.shouldn’t D. needn’t
3.(2016·浙江)George _________ too far . His coffee is still warm .
A.must have gone B. might have gone
C.can’t have gone D. needn’t have gone
4.（2015 • 重庆）You _________ be Carol. You haven’t changed a bit after all these years.
A.must B. can C. will D. shall