2021届高考英语通用版一轮复习考点专讲：考点19情态动词学案

考点19 情态动词
高考频度：★★★☆☆

【命题解读】
高考研究者发现，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。
【命题预测】
情态动词是各地高考试题中的必考项目，每年高考单独命题区的单项填空必有一道考查情态动词的项目。新课标卷主要在语法填空和短文改错中考查。考点依次是：推测(可能性)→请求/允许→必要性→特殊用法。试题的立意不偏不怪，但有效信息越来越隐蔽，语境越来越真实，考查角度越来越细致，这些因素在很大程度上增加了试题的难度。
【复习建议】
1. 真实的语境中对情态动词的理解和把握；
2. 掌握情态动词表示推测和可能性的用法；
3. 掌握情态动词表达＂情感、态度、语气等＂方面的用法。
考向一　can，could与be able to的用法
1．表示能力，意为＂能，会＂。
☞Many people can use the computer.
许多人会用电脑。
☞If you have a good sleep，you will be able to work out this problem.
如果你好好睡一觉，你将能够解出这道题。
☞I could have worked out the problem，but I was too nervous.
我本来可以解决这个问题，但我太紧张了。
2．can/could表示惊讶，常用在否定句和疑问句中。
☞How can you treat me like that?
你怎么能那样对我？
3．can/could表示礼貌地请求别人做某事，意为＂能，可以＂。
☞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。
【易混辨析】
can和be able to 用法上的区别
1. can只有两种时态，即can 和could；而be able to 有多种时态，如was/were able to，will/shall be able to，have/has been able to等。
I’ll be able to drive the car in a week.
Through his diligent work, the deaf-mute has been able to read and write in a sign language.
2. 表示过去通过努力终于做成了某事要用be able to，而不能用can。
I was able to swim to the bank after the boat turned over.
can 和be able to 都可以表示能力。can泛指一般的能力；be able to则主要指具体做到了某件事的能力，其形式主要是靠be 发生变化，所以形式比can 多。
3. can能表猜测，be able to不能。can的这种用法主要用于疑问句和否定句。其肯定形式是must be。
Somebody is knocking at the door. Who can it be?
It can’t be our teacher who is knocking at the door.
4. can 可以表 ＂允许＂，与may可以互换，此时不能用be able to 代替。
—Can / May I sit here?
—Yes, please.

1. (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
【参考答案】C
【答案解析】考查情态动词。句意：在今天的信息时代，数据的丢失有时会对一个公司造成严重的问题。数据丢失造成严重问题是客观上会发生的情况，即“客观可能性”，故该空应用情态动词can。C选项正确。其余情态动词均没有该用法。need需要；should应该，竟然；must必须，肯定。
2. (2017·北京卷·单项填空)Samuel, the tallest boy in our class, ________ easily reach the books on the top shelf.
A. must B. should
C. can D. need
【参考答案】C　
【答案解析】考查情态动词。can表示能力，意为“能够” 。故答案为C。句意：塞缪尔——我们班个子最高的男孩——能够轻松地够到架子顶层上的书。
考向二　may与might的用法
1．表示请求、允许时，might比may的语气更委婉一些，否定回答时要用mustn’t，表示＂不可以＂＂禁止＂＂阻止＂之意。
☞—May I play basketball this afternoon?
—No，you mustn’t.
——今天下午我可以打篮球吗？
——不，不行。
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.
他现在很可能呆在北京。
☞If you think the price of beef is too high，you might as well buy some pork.It depends on you.
如果你认为牛肉太贵的话，你不妨买些猪肉。你自己决定。

might为may的过去式，但也可以代替may，语气较为婉转客气或更加不肯定。
He might not come today. 今天他也许不来了。(语气不肯定)
You might also get a headache when you work too hard. 当你工作太努力时，你也可能患头痛。


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
【参考答案】D
【答案解析】句意：你可能觉得所有的训练都是浪费时间，但是我有100%的把握你以后会感激它的。should应该；need需要；shall将会；may（不确定）可能。所以选D。
考向三　must与need的用法
1．must用于否定句，表示＂禁止＂，表示说话者的命令或指令，语气比较强烈。
☞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。
2．must表示必要性，意为＂必须＂。
☞Progress must lead to a better life and a better way of doing things.
发展一定会促成一种更好的生活，更好的做事情的方法。
3．must表示偏执、固执，意为＂非得，偏要＂。
☞If you must go，at least wait until the storm is over.
如果你非要走的话，至少等到暴风雨结束。

①must开头的疑问句，其否定回答通常用don’t have to或needn’t。而不用mustn’t。
—Must I finish my homework first? 我必须先完成作业吗？
—No, you don’t have to/ needn’t. 不，你不必。
②can和must在表推测时，can一般用于否定句中，而must 常用于肯定句中。
It can not be Li Lei. 那个人不可能是李磊。
It must be Li Lei. 那个人肯定是李磊。

【易混辨析】
must和have to
1. 表示必须、必要。
在回答引出的问句时，如果是否定的，不能用mustn’t（禁止，不准），而用needn’t/don’t have to（不必）.
—Must we hand in our exercise books today?
—Yes, you must.
—No, you don’t have to / you needn’t.
2. must是说话人的主观看法，而have to则强调客观需要。must只有一般现在时，have to有更多的时态形式。
The play isn’t interesting, I really must go now.
I had to work when I was your age.
3. 表示推测、可能性，只用于肯定的陈述句。
You’re Tom’s good friend, so you must know what he likes best.
Your mother must be waiting for you now.
4. need 的用法：
（1）情态动词，＂需要，有必要 ＂，一般用于否定句或疑问句中。
You needn’t come here this afternoon. 你今天下午不必来。
（2）行为动词，＂需要, 有必要＂，可以用于各种句式中。
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？
【巧学妙记】
need的用法助记口诀
实义动词表＂需要＂，后接名、代、不定式。
need后接动名词，主动形式表被动。
情态动词表＂需要＂，没有人称、数之变。
其后直接加动原，多用疑问与否定。

【易混辨析】
dare和need
1. dare作情态动词用时，常用于疑问句、否定句和条件从句中，过去式形式为dared。
How dare you say I’m unfair?
He daren’t speak English before such a crowd, dare he?
If we dared not go there that day, we couldn’t get the beautiful flowers.
2. need 作情态动词用时，常用于疑问句、否定句。在肯定句中一般用must, have to, ought to, should代替。 You needn’t come so early.
—Need I finish the work today?
—Yes, you must. / No, you needn’t.
3. dare和 need作实义动词用时，有人称、时态和数的变化。在肯定句中，dare后面常接带to的不定式。在疑问句和否定句中，dare后面可接带to或不带to的不定式。而need后面只能接带to的不定式。
I dare to swim across this river.
He doesn’t dare (to) answer.
He needs to finish his homework today.

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
【参考答案】C
【答案解析】句意：——你不能再多待会儿吗?——很晚了，我必须得走了。我女儿一个人在家。A. may可能，可以，也许； can能，会；C. must必须，必然要，必定会；D. dare敢，胆敢。结合句意，故选C。
2.You __________be careful with the camera. It costs!
A .must B. may C. can D. will
【参考答案】A
【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。
考向四　will与would的用法
1．表示请求、建议等，would比will委婉客气。
☞Would you mind opening the window for me?
请你给我打开窗户好吗？
2．will和would表示意志、愿望和决心。
☞I will never talk to him again.
我再也不愿意和他说话了。
3．will可以表示一种习惯性的动作，有＂总是＂或＂总要＂之意。
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.
【参考答案】删除let前的to　
【答案解析】would后跟动词原形，故把to删除。
考向五　shall，should与ought to的用法
1．shall用于第一、第三人称疑问句中，表示说话人征求对方的意见和向对方请示。
☞Shall we begin our new lesson today?
我们今天开始上新课好吗？
2．shall用于第二、第三人称陈述句中，表示说话人给对方的命令、警告、允诺或威胁。
☞You shall be punished for what you have done.
你必须为你的所作所为受到惩罚。
3．should表示义务、职责等，意为＂应该＂。
☞You should be strict with yourself as an officer.
作为一名官员，你应该严格要求自己。
4．ought to表示应该。
☞You ought not to be late for such an important meeting.
这么重要的会议你不应该迟到的。
5．shall还可表示法律、规定和条例中规定的＂应该＂。
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。
【易混辨析】
should, ought to
1. should, ought to表示＂应该＂，ought to表示义务或责任，比should语气重。
I should help her because she is in trouble.
You ought to take care of the baby.
2. 表示劝告、建议和命令。should、ought to可通用，但在疑问句中常用should。
You should / ought to go to class right away.
Should I open the window?
3. 表示推测，should、ought to (客观推测)，must(主观推测)。
He must be home by now. (断定他已到家)
He ought to/should be home by now.(不太肯定)
This is where the oil must be.(直爽)
This is where the oil ought to/should be.(含蓄)

考向六　情态动词表推测的用法
1．can用于肯定句中表示客观的可能性，意为＂有时会＂；用于疑问句中可以表示推测，意为＂可能＂，有时表示一种惊讶的语气；用于否定句中也可以表示推测，can’t意为＂不可能＂，语气很强烈。
☞As we all know，an experienced teacher can make mistakes.
众所周知，一位有经验的老师也会犯错。
☞He can’t have left. His coat is here.
他不可能已经走了。他的外套还在这里。
☞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？
2．may/might用于肯定句中可以用来表示不十分肯定的推测，意为＂有可能＂；用于否定句中也可以表示推测，may not意为＂可能不＂，表示一种不太确定的语气。
☞—What are you doing this Saturday?
—I’m not sure，but I might go to the Rolling Stones concert.
——本周六你打算干什么？
——还说不定，但我可能会去滚石音乐会。
3．must表示推测时只能用于肯定句中，意为＂一定，必定＂，表示十分肯定的语气(在疑问句中或否定句中要用can/could)。
☞Someone must have used my umbrella yesterday. I found it wet.
昨天一定有人用了我的雨伞，我发现它湿了。
4．should用来表示推测时意为＂应该＂，即含有＂按道理来说应当如此＂的意思。
☞There shouldn’t be any difficulty about passing the road test since you have practiced a lot in the driving school.
因为你在驾校训练了那么多，通过路考应该没什么困难。
考向七　＂情态动词＋have done＂的用法
情态动词＋have done
用法
must have done
一定做过某事，其否定形式为can’t/couldn’t have done
can/could have done
(1)本来能够做但却未做
(2)可能做过某事
can’t/couldn’t have done
不可能做过某事
may/might have done
或许/可能做过某事
should/ought to have done
本该做但却未做，其否定形式表示本不该做但却做了
needn’t have done
做了本没有必要做的事情
1.＂must have done＂
☞表示对过去事情的肯定推测，译成＂一定做过某事＂，该结构只用于肯定句。
☞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＂
表示对过去事情的否定推测，译成＂不可能做过某事＂。
☞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＂
☞表示对过去行为的怀疑，用于疑问句，译成＂可能做过……吗？＂。
☞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＂
是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。
☞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＂
表示对发生过的事情的推测，意思是＂可能已经＂或＂也许已经＂，用于肯定句中。
☞—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＂
表示对过去事情的推测，might与may意思相同，但可能性更小。多用于虚拟语气结构中。
☞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＂
虚拟语气，表示对过去事情的假设，意思是＂本来会……＂。
☞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＂
意思是＂本来应该做某事，而实际没做＂。＂shouldn’t+have+done＂表示本来不应该做某事，而实际做了。含有指责对方或自责的含义。
☞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。



—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
【参考答案】D
【答案解析】考查情态动词+have done结构。句意：——对不起，妈妈，我面试又失败了。——噢，那太糟糕了，你应该做好充分准备的。A.must必须；B.can可以；C.would将会；D.should应该。can have done＂表示对过去行为的怀疑，用于疑问句，译成＂可能做过……吗？＂；could have done表示对过去事情的假设，意思是本来能够做某事而没有做；must have done＂表示对过去事情的肯定推测，译成＂一定做过某事＂，该结构只用于肯定句；should have done＂的意思是＂本来应该做某事，而实际没做。故选D。


题组一 基础过关
I. 用适当的情态动词填空
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.
II. 单项填空
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?
—Absolutely.
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


题组二能力提升
用适当的情态动词完成下面短文
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__.＂

题组三体验真题
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.
A. daren't B. shouldn't
C. needn't D. mustn't
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


题组一 基础过关
I. 用适当的情态动词填空
1. can 2. Could/Can 3. could 4. Would 5. mustn’t
6. must 7. Shall 8. should 9. Will 10. may
II. 单项填空
1. A 【解析】考查情态动词。句意：你不必让我搭便车。为了锻炼我想走回家。needn’t不必；couldn’t（过去）不能；can’t不能；mustn’t禁止。故选A。
2. D 【解析】考查情态动词。句意：记住在一些国家，你不能带某些颜色的花，因为它们是不幸运的。这里表示＂禁止＂用mustn’t。could not不能（表示能力）； needn’t不必；may not可能不。故选D。
3. C 【解析】考查情态动词。句意：作为中国的年轻一代，难道他们不应该接受这个国家提供的所有挑战和机会吗？should表示＂应该＂，故C项正确。
4. C 【解析】考查情态动词。句意：——你偏要现在打断吗？难道你没有看见我在打电话吗？——对不起，但是这是紧急事情。Can 能够；Should应该；Must必须，偏要；Would将会。故选C。
5. B 【解析】考查情态动词。句意：据说，人们可能通过锻炼减少得一些严重疾病的危险。这里要用情态动词can表示＂可能会＂。must必须；would将会；need需要。故选B。
6. D 【解析】考查情态动词。句意：我十分震惊，那个小孩子竟然对他的父母说了那样粗鲁的话。由句意可知这里表示＂惊讶＂，故用should。
7. B 【解析】考查情态动词。句意：一定是我乘坐公共汽车的时候手机被偷了。我到处都找不到它。can能；must必须；should应该；would将会。must have done过去一定做某事。故选B。
8. D 【解析】考查情态动词+have done。句意：——你本不必带这么多现金在身边。你知道那家商店接受支票。couldn’t have taken过去不可能做了；wouldn’t have taken过去不会做而做了；shouldn’t have taken本不应该做某事而做了；needn’t have taken过去本不必做某事而做了。故选D。
9. D 【解析】考查情态动词+完成式的用法。句意：没有你的帮助，我不可能按时完成我们的任务。我再怎么感谢你都不过。对过去事情的否定推测用couldn’t have doneb表示过去不可能做某事。故选D。
10. B 【解析】考查情态动词+have done。句意：——Bob没有通过考试。——真遗憾！他本应该努力学习的。should have done意为＂过去本应该做却没有做＂，would have done意为＂过去本来会做却没有做＂；could have done意为＂过去本可能做却没有做＂。故选B。
题组二能力提升
适当的情态动词完成下面短文
1.should　 2.might　 3.could　 4.might　 5.Shall
6.shouldn’t　 7.can　 8.May/Can　 9.must　 10.can
题组三 体验真题
1.C　【解析】 考查情态动词。根据“I can do it in the morning.”可知现在没必要打扫房间。故选C项。needn't不必；daren't不敢；shouldn't不应该；mustn't不准，禁止。句意：我的房间很乱，不过今晚在我出去之前，我没必要打扫它。我可以在(明天)早晨打扫。
2.B 【解析】句意：这真是令人生气的；我不能进入你推荐的数据库。wouldn’t不愿意；couldn’t不能；shouldn’t不应该；needn’t不必。故选B。
3.C 【答案】句意：乔治不可能走得太远了。他的咖啡仍然是温的。can’t have done是对过去的否定推测；must have done过去一定做了某事；might have done过去可能做了某事；needn’t have done过去本不必做某事。故选C。
4.D 【解析】句意：你肯定是卡罗，这些年你一点也没有变化。must表示对现在的肯定推测。