第二讲语法- 情态动词
情态动词表示说话人的能力、义务、必要、猜测等语气或情感。情态动词必须和动词原形一起构成谓语，无人称和数的变化。其使用要点如下：
一、情态动词考点解析
can, could和be able to的用法
1．can和could表示“能，会”，有一般现在时和一般过去时两种时态，在将来时和完成时中必须用be able to。表“能力”时can与be able to换用。
例如：Can you type? =Are you able to type?
We’ll be able to get you a job soon.（在将来时中不可用can）
He has been able to finish the work on time.（在完成时中不可用can）2．“can/could+ have done”表“本能够做某事而没有做”。
例如：You could have been more careful. 你本能够更细心的。
3．“can’t/couldn’t+ have done”表“不可能做了某事”。
例如：Without your help, I can’t have made such great progress.
没有你的帮助，我不可能取得这么大的进步。
must和have to的用法
1．must和have to都表示“必须，不得不”。must强调主观性；have to强调客观需要。must只用于一般现在时，而have to有更多的时态形式。
例如：I must learn another language.（主观想法：我想要）
I have to learn another language.（客观需要：我不得不）
It’ll have to be finished in two days.（have to用于将来时中）
He has had to reconsider his position.（have to用于现在完成时）
2．两者的否定意义不同：mustn’t表示“禁止；不可以”，而don’t have to表示“不必”，意思相当needn’t。
例如：You mustn’t go.你决不可以去。
You don’t have to go.你不必去。
3．“must be +形容词或名词”表示对现在情况的肯定推测和判断；否定的推测用can’t。
例如：What he said must be true. 他说的一定是真的。
What he said can’t be true.他说的不可能是真的。
This must be Jim’s pen.这一定是吉姆的笔。
4．“must+have done”表示对过去情况的肯定推测；“can’t/couldn’t+have done”则表示对过去情况的否定推测。
例如：The ground is wet. It must have rained last night.
地面很湿，昨晚一定下过雨。
He can’t find his key. He must have left it in the car.
他找不到钥匙了一定是丢在车上了。
He can’t have finished the work in such a short time.
他不可能在这么短的时间内完成了这份工作。
should和ought to的用法
1．两者都表示“应该”，但should语气比ought to重，在日常交际中多用should，表一般的忠告。ought to 否定形式为ought not to。
You ought to respect the old. 你应该尊重老人。
You ought not to tell him about it. 你不应该告诉他那件事。
2．“should/ought to+have done ”表示“过去本应该做某事而没有做”；否定式“shouldn’t/ ought not to+have done”表“本不该做某事却做了”。
例如：I should have finished the work earlier.
我本应早点完成这项工作。
His wife is selfish. He oug htn’t to have married her.
他的妻子很自私，他本不该娶她的。
dare作情态动词和行为动词的用法
1．dare作情态动词主要用在否定句和疑问句中，其否定式是“dare not+动词原形”
表“敢；竟敢”。
例如：She dare not speak in public. 她不敢在公众面前讲话。
How da re you do such a thing? 你怎敢做这样的事？
2．dare作为行为动词时，肯定式为“dare to do sth.”，to可以省略；其否定式为“don’t dare (to) do/ doesn’t dare (to) do/ didn’t dare (to) do”。
例如：She dares (to) swim in that river. 她敢于在那条河里游泳。
I don’t dare (to) speak of it. 我不敢说那件事。
need作情态动词和行为动词的用法
1. need作情态动词，常用于否定句和疑问句中，其否定式为“needn’t+动词原形”。
例如：You needn’t do anything here.你在这里什么也不要做。
You needn’t go if you don’t want to.你不想去就不必去。
You needn’t do it at once, need you?你不必马上做，是吗？
2．need作行为动词，其否定式为“don’t need to do…”。后面接动词不定式，表主动；接动名词表被动。
例如：You don’t need to do it yourself.你不必亲自做这件事。
I need to tell them the news. 我需要告诉他们这个消息。
This table needs painting.=This table needs to be painted.
这张桌子需要刷新。
情态动词的完成时和进行时
1．情态动词的完成时
must + have done（一定做了……）推测过去情况的肯定发生了。
may/ might + have done（也许做了……）推测过去情况也许发生了。
can/could + have done（本能够做了……）本能够做却没做。
can’t/ couldn’t + have done（不可能做了……）推测过去情况不可能发生。
should/ ought to + have done（本该做了……）过去本应该发生的而未发生。
shouldn’t / oughtn’t to + have done（本不该做了……）
过去本不应该发生的而发生了。
needn’t + have done（本不必做了……）本不必做的事却做了。
2．情态动词的进行时
must be doing一定在做某事。
may be doing可能在做某事。
can’t be doing不可能在做某事。
shouldn’t be doing不应该在做某事
公外真题解析;
1.You___me because I didn’t say that. ( 2002-29 )
A. must misunderstand
B. must be understanding
C. must have understood
D. had to misunderstand
2. Without his wise mother, he _____ such a successful scientist.
A. would not become
B. should not have become
C. may not have become
D. could not have become
3. Go and get some water, _____?(2003)
A. don’t you
B. shall you
C. can’t you
D. won’t you
4. I ___ a little earlier, but 1 met a friend of mine on the way. (2006-23)
A. should arrive
B. would be arriving
C. could have arrived
D. arrived
5. I didn't see him at the meeting yesterday afternoon. He___it. (2006-42)
A. mustn’t attend
B. can ' t have attended
C. wouldn’t have attended
D. needn' t have attended
6. You ____ me because I didn’t say that.(2007)
A. must understand
B. must be understanding
C. must have understood
D. had to misunderstand
7. I'm not surprised you failed the exam. You ____have worked harder. (2008-21)
A. should
B. must
C. would
D. ought
8. You ___not have seen her yesterday, for she was abroad. (2009-12)
A. must
B. should
C. could
D. would
9. He must have stayed up late last night, ______he?(2011)
A. mustn’t
B. needn’t
C. hasn’t
D. didn’t
10. Let’s put the matter to the vote and not waste our time arguing about it, ______? (2012)
A. shall we
B. can we
C. may I
D. will you
11. I’m sorry that he _____ in such poor health.(2013)
A. are
B. shall be
C. were
D. should be
1-5 CDDCB 6-11CACDAD
专业情态动词真题：
1. If you ____ see Xiao Li in Beijing, please let him give me a call.
A. would
B. should
C. will
D. shall
2. This kind of work is hard and dangerous. But you would become rich ____.
A. would you succeed
B. ought you to succeed
C. might you succeed
D. should you succeed
3. Father said such a thing ____ to happen yesterday.
A. ought to be not allowed
B. ought not to be allowed
C. ought to be allowed not
D. not ought to be allowed
4. I didn’t see him at the meeting yesterday afternoon. He ____ it.
A. mustn’t attend
B. can’t have attended
C. wouldn’t have attended
D. needn’t have attended
5. ____you find yourself in a condition of being troubled or worried about some trifles, please cultivate a hobby.
A. Could
B. Should
C. Might
D. May
6. He used to ____ in the countryside.
A. be living
B. live
C. living
D. having lived
7. John did very well in the exam. He ____ very hard all these days.
A. would have worked
B. would work
C. must work
D. must have worked
8. I wish to call on you tonight, ____?
A. have I
B. may I
C. don’t I
D. would I
9. Search finding show we spend about two hours dreaming every night, no matter what we __ have done during the day.(2007)
A. may
B. should
C. could
D. must
10. Don’t forget to walk the dog while I am away, ___?
A. will you
B. do you
C. shall you
D. can you
11. But for the favorable weather, we _____ in such a good harvest.(2008)
A. can’t get
B. couldn’t get
C. couldn’t have got
D. could have got
12. Without computers, we ____ the tremendous medical advancement in the few decades.(2009)
A. would not make
B. will not have made
C. could not make
D. couldn’t have made
13. Research findings show we spend about two hours dreaming every night, no matter what we _____ during the day. (2010)
A. must have done
B. would have done
C. should have done
D. may have done
14. “You realize that you were driving at 100 mph, don’t’ you?” (2013)
“No, office, I ____. This car can’t do more than 80.”
A. couldn’t have been
B. may not have been
C. didn’t need to be
D. needn’t have been
Keys: 1-5BDBBB 6-10 BDBAA 11-14CDDA
三、模拟训练
1. From the tears in Nerd’s eyes, we can deduce that something sad____.
A. must have occurred
B. would have occurred
C. might be occurred
D. should occur
2. “Must we do it now?” “No, you_____.”
A. won’t
B. needn’t
C. mustn’t
D. don’t
3. You____read that article if you don’t want to.
A. haven’t
B. can’t
C. mustn’t
D. needn’t
4. The teacher said that the students____understand the problem very well.
A. can
B. could
C. shall
D. dare
5. You____make up your mind right away.
A. have not to
B. not have to
C. have to not
D. don’t have to
6. He_____be so impolite to your parents.
A. should not
B. can not
C. ought to not
D. may not
7. He is afraid of his father; he_____speak to him.
A. dare not
B. dares not
C. didn’t dare
D. can not
8. I_____get up early, but now I often miss my breakfast.
A. must
B. dare
C. used to
D. use to
9. Smoking_____in public.
A. should be allowed not
B. should be not allowed
C. should not be allowed
D. not should be allowed
10. The children_____while their parents are away.
A. should take good care of
B. should be taken good care
C. should be taken good care of
D. should taken good care
11. “Bob translated the book into English.”
“He_____because he doesn’t understand English.”
A. can’t have do that
B. may not have done that
C. must have done that
D. can’t have done that
12. Why did he miss his English class yesterday? He____.
A. can have forgotten about it
B. may have forgotten about it
C. may forget about it
D. could have forgotten about it
13. He left here at 5: 00 p.m. yesterday. He_____by seven this morning.
A. can have arrived
B. may not arrive
C. must have arrived
D. must arrive
14. Mary was very unhappy last week. Susan_____her the truth.
A. can have told
B. must have told
C. may tell
D. must tell
15. You_____with them. Why didn’t you go?
A. could have gone
B. can go
C. must have gone
D. must go
16. You____the examination if you had worked harder.
A. can pass
B. must pass
C. could have passed
D. may pass
17. It’s no wonder that he didn’t pass his examination. He_____.
A. could study hard
B. may not study hard
C. must have studied hard
D. should have studied hard
18. This box is too heavy, _____give me a hand?
A. would you mind
B. would you please
C. will you like to
D. will you please to
19. Research findings show we spend about two hours dreaming every night, no matter
what we_____ during the day.
A. should have done
B. would have done
C. may have done
D. must have done
20. Some women____a good salary in a job instead of staying home, but they decided not
to work for the sake of the family.
A. would make
B. must make
C. could have made
D. should have made
21. If you ____ see Xiao Li in Beijing, please let him give me a call.
A. would
B. should
C. will
D. shall
22. This kind of work is hard and dangerous. But you would become rich ____.
A. would you succeed
B. ought you to succeed
C. might you succeed
D. should you succeed
23. Father said such a thing ____ to happen yesterday.
A. ought to be not allowed
B. ought not to be allowed
C. ought to be allowed not
D. not ought to be allowed
24.____ you find yourself in a condition of being troubled or worried about some trifles,
please cultivate a hobby.
A. Could
B. Should
C. Might
D. May
25. He used to ____ in the countryside.
A. be living
B. live
C. living
D. having lived
26. John did very well in the exam. He ____ very hard all these days.
A. would have worked
B. would work
C. must work
D. must have worked
27. I wish to call on you tonight, ____?
A. have I
B. may I
C. don’t I
D. would I
28. Research finding show we spend about two hours dreaming every night, no matter
what we ____ have done during the day.
A. may
B. should
C. could
D. must
29. Don’t forget to walk the dog while I am away, ___?
A. will you
B. do you
C. shall you
D. can you
30. She looks tired. She ___ last night.
A. should have stayed up late
B. must have stayed up late
C. need have stayed up late
D. would have stayed up late
31. I was really anxious about you. You ___ home without a word.
A. mustn’t leave
B. shouldn’t have left
C. couldn’t have left
D. needn’t leave
32. Whenever Tom knew I was in trouble, he ___ always lend me a hand.
A. might
B. would
C. could
D. should
33. They have done things that they ought ____.
A. not to do
B. not to be done
C. not to have done
D. not having done
34.—Where is my dictionary? I remember I put it here yesterday.
—You _____ it in the wrong place.
A. must put
B. should have put
C. might put
D. might have put
35. The teacher _____ have thought Johnson was worth it or she wouldn’t have wasted
time on him.
A. should
B. can
C. would
D. must
Keys:1—5 ABDBD 6—10 AACCC 11—15 DBCBA 16—20 CDBCC 21—25BDBBB 26—30DBAAB 31—35BCCDD
一、选择题 1．It is 11:00 p.m now. Peter hasn't come back yet. His mother ______ be very mad at him. A．may B．can C．must D．need 2．—Have you heard about the temperature of the earth will rise to 59℃ in 2020?—Don’t worry! The news _______ be true. A．must not B．may not C．needn’t D．will not 3．-Listen! A wolf is crying! -It _______ be a wolf, because a wolf never comes out at this time. A．mustn’t B．needn’t C．can’t D．don’t 4．I’ve bought a nice necklace for Jo’s birthday. She _____like it, but I’m not sure. A．can B．may be C．might D．must 5．---Mum, must I finish my homework today? ---No, you . Tomorrow is Sunday and you may have a rest today. A．shouldn’t B．mustn’t C．can’t D．don’t have to 6．You look quite tired. You'd better ________ a good rest. A．stop to have B．stop having C．to stop to have D．to stop having 7．—Tom, we’re going shopping at eight, right? —Yeah, but I ______ be a little late, so don’t wait for me. A．may B．should C．mustn’t 8．You should________ the teacher________being late for school. A．apology to, about B．apologize to, for C．apologies to, for D．apologize to, on 9．—Can you come to my party on Saturday afternoon? —Sorry, I can’t. I ________ meet my friends. A．can’t B．might have to C．needn’t 10．— I wonder if these are Jim's glasses. —They _____his. He doesn't wear glasses. A．might be B．could be C．can't be 11．—The book report is very important. You ________ write it carefully. —But I ________ hand it in now. A．must; must B．have to; must C．must; have to D．have to; have to 12．Even the top student can't work out this problem, so it________ be too difficult. A．must B．may C．can D．need 13．—________ I borrow the books from the library, Miss Yang? —Sorry, you________. These books are only for members of the English Club. A．Can; couldn’t B．Could; can’t C．Could; could n’t D．Can; needn’t
一、选择题 1．—Jenny, we buy Mom presents. We can clean the house from top to bottom. —Good idea! It’s a special present for Mother’s Day. A．can’t B．mustn’t C．shouldn’t D．needn’t 2．-Listen! A wolf is crying! -It _______ be a wolf, because a wolf never comes out at this time. A．mustn’t B．needn’t C．can’t D．don’t 3．―I didn’t pass the driving test again. ―Don't worry. Just like the weather, life be beautiful all the time. A．can't B．needn't C．shouldn't D．mustn't 4．—________your house be cleaned right now？ —No,it needn't.It may be cleaned this afternoon．（） A．Must B．May C．Can 5．—Is that cap Bob’s? —No, it ________ be his. His is blue. A．can’t B．mustn’t C．needn’t D．may not 6．（江苏省无锡市锡北片2017届九年级下学期期中考试）—Where are you going for your summer holiday? —We go to Yun Nan, but we haven’t decided yet. A．should B．will C．may D．must 7．—How nice the building is! What is it for? —It ________ a hotel. But I’m not sure. A．must be B．have to be C．may be D．can be 8．—______ you please tell me something about the life in Canada or America? —Sorry, I______. I don’t know either. I’m from Australia. A．Could; couldn’t B．Can; couldn’t C．Could; can’t D．Can; mustn’t 9．— I would like________ to see a movie. —It’s too late. You’d better ________alone. A．to go, go B．go, not go C．to go, not go D．going, go 10．— I wonder if these are Jim's glasses. —They _____his. He doesn't wear glasses. A．might be B．could be C．can't be 11．I see the blackboard. I need to have my glasses. A．can B．can’t C．must D．mustn’t 12．I’m sorry, childre n over 1.4 meters________pay the full price for the show. A．may B．must C．can D．ought to 13．—Jack must be in his office, I think. —No, he be in the office. He flew to Canada this morning.
必修三unit2语法讲解情态动词用法（二） 、ought to的用法 1. ought to应该”与should相比较ought to语气重,偏重责任、义务、 道德、法律”等方面，意为应该” ①We ought to stop polluti ng n ature.我们应该停止污染大自然。 2. ought to表示较大的可能性。 ①Mary ought to be here soon.玛丽应该很快就来了。 ［点津］用ought to表示推断时，语气较肯定，通常指的是一种合乎逻辑的 可能性（与should表推断时相似）,有时可译为很可能；准是”语气比must要弱）。 3. ought to的否定形式为ought not to或ought n't to,其一般疑问句形式是将ought置于主语前。 ①We ought not to start so late.我们不该这么晚动身。 4. 在反意疑问句中,常省掉to用ought n't或should n't。 ① He ought to take back what he has said, ought n' t/should n't he? 他应该收回他说的话，是吗？ 1 —1.写出下面句中黑体部分的意义 ① To keep fit, weought to lear n more about our body. _____ ① Youought not to do such a thing. _______ ① Itought to be a close game. _______ 1 —2.用ought完成句子 ①（尔不该责备他。You __________ （scold ）him. ①我明天该动身吗？一_______________ （_leave ［tomorrow? 是的，你应该。一Yes, you ought to ①我们现在应该走，是吗？We ought to go now, ______________ _? 二、have to, don't have to 与must n't 的用法 1. have to（口语中常用have got to）表示客观需要做的事情，意为必须；不 得不”有时态、人称和数的变化，其否定式和疑问式应由助动词do构成。 ① My brother was very ill, so I had to call the doctor in the middle of the ni ght. 我弟弟病了，我不得不半夜里把医生请来。
一、选择题 1．— I would like________ to see a movie. —It’s too late. You’d better ________alone. A．to go, go B．go, not go C．to go, not go D．going, go 2．-Listen! A wolf is crying! -It _______ be a wolf, because a wolf never comes out at this time. A．mustn’t B．needn’t C．can’t D．don’t 3．(2018·山东临沂) Could you please speak a little louder? I ______ hear you very well. A．can’t B．mustn’t C．shouldn’t D．needn’t 4．— Do you think it is safe to shop online? — I think so. On Taobao, customers return goods with no questions asked，but they ______ pay delivery costs. A．can’t; can B．must; must C．can; have to D．mustn’t; can 5．The designer has tried every possible way to make the robot light, so you _____ worry about its weight. A．must B．may C．can’t D．needn’t 6．A: Is Jim coming by train? B: I’m not sure. He _______ drive his car. A．must B．may C．need D．should 7．—I can't stop smoking, doctor. —For your health, I'm afraid you ________. A．must B．can C．may D．need 8．From March 23rd, 2013, anyone under the age of 14 ________ go into Disneyland alone. A．couldn’t B．mustn’t C．needn’t D．mightn’t 9．—Hi, Lucy, may I sit here? —No, ________. The seats are for teachers and parents. A．you needn't B．you aren't C．you mustn't D．you don't 10．—Must I finish my homework this evening? —No,you ________.You have a three﹣day holiday. A．won't B．mustn't C．needn't 11．—Sorry, Ms Wang. I left my homework at home. Must I hand it in today? —No, you_______ . You_______ bring it here tomorrow. A．mustn’t; should B．needn’t; must C．mustn’t; may D．needn’t; can 12．－Mum, must I stay there the whole day? －No, you__________. You__________ come back after lunch, if you like. A．mustn’t; can B．needn’t; must C．needn’t; may 13．—Jenny, we buy Mom presents. We can clean the house from top to bottom.
情态动词 有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。情态动词无人称和数的变化；不能单独使用，必须与其后的动词原形构成谓语。 情态动词 句和疑问句中表示请求，允许，意为“能够” could 是can 的过去式，意为“能、会”，表示过去的水平在疑问句中表示委婉请求 may 表示请求、许可，意为“能够”表示推测，常用于肯定句中，意为“可能、也许” might 是may的过去式,表推测，常用于肯定句中，意为“可能、也许”must 表示主观看法，意为“必须、应该”表有把握的推测，用语肯定句dare 表示敢于，主要用于否定句和疑问句中 should 意为“应该”，表示要求和命令表示劝告、建议 had better 意为“最好”，表示建议 used to意为“过去常常，表示过去的动作、行为 考点一情态动词知识清单 情态动词有具体的词义，但也同助动词一样，需要与其他词语一起构成句子的谓语，另外情态动词没哟人称和数的变化，情态动词后必须跟动词原形。 1. can 的用法 （1）表示水平、许可、可能性。表示水平时一般译为“能、会”，即有种水平，尤其是生来具备的水平，此时may 和must 均不可代替它。（2）表示可能、能够。如：I can finish it in an hour. （3）表示许可，常在口语中。如：You can use my dictionary. （4）表示推测，意为“可能”，常用于否定句和疑问句中，此时can’t 译为“不可能”。 2.could的用法 （1）can的过去式，意为“能、会”，表示过去的水平。 （2）could 在疑问句中，表示委婉的语气，此时没有过去式的意思。 3.may的用法 （1）表示请求、许可，比can 正式， （2）表示推测，谈论可能性，意为“可能，或许”，一般用于肯定句中。 （3）may的过去式为might ，表示推测时。可能性低于may 。 4. must的用法 （1）must 表示主观看法，意为“必须、一定”。 （2）其否定形式mustn’t表示“一定不要”“千万别”“禁止, 不许”.（3）对must引导的疑问句，肯定回答为must，否定回答为needn’t或don’t have to . （4）must 表示有把握的推测，用于肯定句。当must 表示肯定的判断、推测时，其反意疑问句要用实际问句的助动词来构成。 She must have finished writing, hasn’t she? 5. need的用法 （1）need 表示需要、必须，主要用于否定句和疑问句中，其否定形式为needn’t，意为“没有必要，不必”。用need 提问时，肯定回答为must，否定回答为needn’t。如：----Need I stay here any longer? ----Yes, you must .-----No. you needn’t . (2) need 还能够作实义动词，此时有人称、数和时态的变化，后边多接动词不定式。 6. dare 的用法dare意为“敢、敢于”,用法近似于need，有两种词性： （1）dare 作为情态动词，多用于否定句、疑问句或条件句中，无第三人称单数形式，只有一般现在时和一般过去时。 （2）dare 作为实义动词，此时有人称、数即时态的变化。注意：在口语中，dare 的各种形式常与不带to 的不定式连用。Do you dare tell her what I said? 7. shall 的用法 （1）shall 表示征求对方意见（多用于第一、三人称）， Shall we go out for a walk? （2）表示决心、警告、命令（多用于第二、三人称）， No one shall bring your beepers or mobile phones in the exam. 8. should的用法 （1） should 意为“应该”，可表示劝告、建议、义务、责任等。We should protect the environment. （2） should (would)like to do sth. 表示“想要、愿意做某事”，常用于口语中。Would you like to go with me? 你想和我一起去吗？ （3）Should have done 表示对过去动作的责备、批评。 You should have finished your homework. 9. will 的用法 will表示意愿、意志、打算，可用于多种人称。 I will help you if I’m free this afternoon. 10. had better 的用法 had better 意为“最好”，没有人称的变化，后面接不带to 的不定式，其否定形式为：had better not。 We had better go now. You had better not give the book to him. 考点二含有情态动词的疑问句 1. 由can、may、must构成的疑问句 （1）句式：Can/ May/ Must…+ 主语+动词原形+….？如：Can you repair the car? Could he be a good student? May I borrow your ruler?Must we clean the room now? （2）对may 引出的问句，能够有下列回答方式：Yes, of course. Yes, certainly.Sure.No, you mustn’t.No, you can’t. （3）对must引出的疑问句，回答为：Yes, …must.No,…needn’t/don’t have to. 2. will，would，shall 的用法 （1）will 在一般疑问句中表示客气的“请求、劝说”。would 是will 的过去式，语气更加客气、委婉。Would you show me your picture book? Will you please give me a call? （2）对will/ would you…的回答方式有以下几种：Yes, I will. (No, I won’t.)Sure . (I’m sorry , I can’t.)All right.Certainly. (No, thank you .) Yes, please. （3）shall引出的疑问句用于第一人称，表示征求对方意见或客气的请求。其回答方式有以下几种：Yes, please.All right. No, thank you. 考点三不同情态动词的否定意义也不同 1. （1）can’t可译为“不会”，如：I can’t play basketball. 我不会打篮球。（2）当句子表推测时，用can’t表达不可能，He can’t be ill. He is playing chess with Tom.（3）can’t还可用来回答“ May I …?”这样的问句。May I come in ?No, you mustn’t. / can’t.（4）can’t还可用于固定习语中。She can’t help crying. 2.may 的否定式为may not ，译成“可能不”，He may not be at home. 3.（1）mustn’t表示不许，不可。He mustn’t leave his room.
Modal Verbs 情态动词有can (could), may (might), must (must), have to, shall (should), will (would), need (need), dare (dared), ought to 等。情态动词无人称和数的变化。它不能单独使用，必须跟其后的动词原形构成谓语。情态动词的具体用法如下： 一、can, could 1、表示能力。 a. Can you speak English? b. Can you finish this work tonight? c. Man cannot live without air. Note:
(1) can表示能力时，可用be able to 代替。 a. I’ll not be able to come this afternoon. (2) 当我们要表示“某件事情已经 成功”时，应用was/ were able to , 不能用could a. He saw well and he was able to swim to the river when the flood happened. b. He was able to go to the party yesterday evening and he enjoyed himself very much. 2、表示客观可能性
a. People who live near airports can have their hearing harmed. b. The boy can sometimes be very naughty. （表示某人或某物一时的情况，“有时会。。。”） c. The invention can be improve d. d. Even experts can make mistakes. e. He can’t be in Beijing now because I saw him a moment ago. f. He had a lot of work to do last night, so he couldn’t have gone to see a film. Note: 在肯定句中用can表示可能性时，其含义是理论上的可能性，不表示
英语《情态动词》语法知识及英语提分方法 情态动词 一、can和could 1、can的用法 （1）表示体力和脑力方面的能力。 （2）表示对现在的动作或状态进行主观的猜测，主要用在否定句和疑问句中。（3）表示可能性，理论上的可能性，意为“有时候可能会”，可用于肯定句。（4）表示允许，意思与may接近。 （5）表示说话人的推测、怀疑、惊异、猜测或不肯定等，主要用于否定句、疑问句或感叹句中。 （6）can的特殊句型 cannot…too / enough表示“无论怎么。。。也不过分”。“越。。。越好”。 cannot but+ do sth.表示“不得不，只好”。 2、could的用法 （1）表示能力，指的是过去时间。 （2）表示允许，指的是过去时间。 （3）表示可能，可以指过去时间，也可以指现在时间，表示语气缓和。 （4）委婉客气地提出问题或陈述看法，指的是现在时间。主要用于疑问句，回答时用can。 3、can与could的区别 can表推测时只用于否定句和疑问句（could无此限制）。couldn’t的可能性比can’t 小。 4、can与be able to的区别
（1）现在时：无区别，但后者不常用。 （2）完成时;can没有完成时，此时要用have（has,had）been able to。 （3）将来时：can没有将来时，要用will be able to。 （4）过去时：could表示一般能力，was/were able to 表示在具体场合通过努力成功做成某事的能力。 二、may 和might 1、may的用法 （1）表示询问或说明一件事可不可以做。 （2）表示一件事或许会发生或某种情况可能会存在，通常用在肯定句和否定句中。 注意：表示可能性时，can’t语气强，表示“不可能”，may not语气弱，表示“可能不”。 2、might的用法 （1）表示询问或允许，指的是过去时间。 （2）表示可能发生的事，可以指过去时间，也可以指现在时间，语气更加不肯定，可能性比may小一些。 3、may与might的特殊用法 （1）“may+主语+动词原形”表示祝愿。 （2）“may/ might well+动词原形”表示（完全）能，很可能。 （3）“may/ might as well+动词原形”表示最好，满可以，倒不如。 （4）may be 是“情态动词+系动词be”结构，表示“可能有，可能在”，否定式为may not be。 maybe是一个词，为副词，意为“大概，或许，可能”，在句中作状语。
情态动词的用法 【真题再现】 1. —I know by what time you want the project to be done? (2014 连云港) — By the day after tomorrow. you finish it on time? A. May; Can B. Must; Need C. Could; Must D. Need; Would 2. I follow you. Would you please repeat it? (2014 河北) A. can't B. mustn't C. needn't D. shouldn't 3. — Who's singing in the garden? (2014 长沙) — It be Mr. Brown. He always practices singing at this time. A. must B. can't C. need 4. —May I take this magazine out of the reading room? (2014 苏州) —No, you _________. You read it in here. A. mightn't B. won't C. needn't D. mustn't 5. You _________ touch an electric fire. It's dangerous. (2014 沈阳) A. need B. must C. needn't D. mustn't 6. —_________ you come with me to Lang Lang's piano concert this evening? (2014 广东) — I'd love to, but I have to study for my math test. A. Should B. May C. Must D. Can 7. Children _________ sit in the front seat of a car. It's too dangerous. (2014 重庆) A. need B. needn't C. must D. mustn't 8. — Look, someone left a book.(2014 菏泽) —Oh, yeah … This book _________ be Kitty’s. Only she likes to read this kind of books. A. can B. must C. may D. might 9. Look! The traffic light has turned red．We_________ stop our car．(2015 广东) A．can B．can’t C．must D．mustn’t 10. — Do you have any plans for this Sunday? (2015 安徽) —I’m not sure. I _________ go to the countryside to see my grandmother. A. can B. must C. may D. need 11. As middle school students, we _________ be afraid of difficulties if we want to make our dreams come true. (2015 哈尔滨) A．must B．shouldn’t C．need 12. You return the book now. You can keep it until next week if you like.(2015 青岛) A. have to B. can’t C. mustn’t D. needn’t 13．—Mom, must I go shopping with you? (2015 南京) —No, you ．You can watch the film Big Hero 6 with your friends． A．needn’t B．can’t C．shouldn’t D．mustn’t 14. Harry’s been driving all day—he be tired.(2015杭州) A. need B. can C. shall D. must 15. It’s surprising that Mr. Ma’s little daughter speak English so well. (2015 重庆) A. must B. can C. mustn’t D. can’t 【答案与解析】 1. A。句意：——我可以知道你想这个项目何时完成吗？——到后天。你能按时完成吗？may可以；can能够；must必须；could用于一般疑问句通常表示请求；need需要。题干问句是请求，可用may或者could，排除B、D两项；答句是询问能否按时完成任务，应选can。
最新英语语法情态动词归纳总结 一、单项选择情态动词 1．Mr. Smith is almost on time for everything. How ________ it be that he was late for the meeting? A．can B．should C．may D．must 【答案】A 【解析】 【详解】 考查情态动词辨析。句意：史密斯先生几乎任何事情都是准时的。他怎么可能开会迟到了？ A. can可能，可能性，表示可能性时，常用于否定句和疑问句中，且有时还带有“惊奇、不相信” 等感情色彩。B. should 应该； C. may也许，表示可能性时常用于肯定句中，不用于疑问句中。D.must常用于肯定句中表推测，“一定……”的意思；本题是强调句型的一个变式：强调其特殊疑问句how的形式。根据前句“斯密斯先生几乎是很准时”可推测出“怎么可能开会迟到呢？”。根据句意可知，用于疑问句中的“可能性”且有不相信的色彩，四个选项只有“can”符合题意。故选A 【点睛】 情态动词就是表示说话者对事情的一种看法，也就是一种语气。情态动词的用法一直是命题者常设置的考点和重点，平时要加强记忆。 2．--- Oh, my God! I just missed the last bus back home. --- That’s really bad. I’m sure you ______ it, but you just didn’t hurry up. A．had caught B．could have caught C．could catch D．can catch 【答案】B 【解析】 【详解】 考查情态动词+have done结构。句意：——哦,我的上帝!我刚好错过了回家的末班车。——这是非常糟糕的。我肯定你能赶上，但你就是不抓紧。could have done“本来能做而没有做”。故选B。 3．-- Did Jim come? -- I don’t know. He _______ while I was out. A．might have come B．might come C．must have come D．should have come 【答案】A 【解析】 【详解】 考查情态动词推测用法。句意：Jim来了吗？--我不知道，在我不在的时候，可能来过。根据前文I don’t kn ow.可知，说话者不知道Jim来没来，因此后文推测来过，但是语气很不确定，故可知选A。对过去情况的推测为情态动词+have done，must have done 一定做了某
英语情态动词的用法大全附解析 一、初中英语情态动词 1．—We've got everything ready for the picnic. —Do you mean I __________ bring anything with me? A. can't B. mustn't C. couldn't D. needn't 【答案】 D 【解析】【分析】句意：—我们已经为野餐准备好了一切。—你的意思是我不必带任何东西吗？A. can't 不能；B. mustn't 表示禁止，一定不要；C. couldn't不能，表示过去时态；D. needn't不必。结合句意，故选D。 【点评】本题考查情态动词的用法。 2．—How amazing this robot is! —Wow, it has video cameras in its eyes, so it “see” and interact with pe ople. A. may B. can C. must D. should 【答案】 B 【解析】【分析】句意：—这个机器人多么惊人啊！—哇，在它的眼睛里有摄像机，因此它能看见和人打交道。A. may 可以，可能；表示许可，B. can 能；表示能力，C. must 必须；D. should应该；根据it has video cameras in its eyes,可知是有能力看见，故选B。 【点评】考查情态动词辨析。熟记情态动词的含义和用法。 3．—Where is George? —He _______ be here just now. His coffee is still warm. A. need B. can't C. must D. shouldn't 【答案】 C 【解析】【分析】句意：——乔治在哪里？——他刚才一定在这里，他的咖啡还是热的。A. need需要； B. can't 不能，不可能（表示推测）； C. must 必须，一定（表示推测）； D. shouldn't不应该；根据His coffee is still warm.可知表示肯定推测一定在这儿；故答案为C。 【点评】考查情态动词。掌握情态动词表推测时的意义和用法。 4．— Sorry, I forgot to take money with me. Maybe I can't buy the book you like. — Mum, you ______ worry about it. We can pay by Alipay （支付宝）. A. can't B. needn't C. mustn't D. shouldn't 【答案】 B 【解析】【分析】句意：——对不起，我忘记带钱了。也许我不能买你喜欢的书。——妈妈，你不用担心。我们可以用支付宝支付。A. can't不能，指不允许或否定推测；B. needn't 不需，指没必要；C. mustn't不能，表禁止；D. shouldn't不应该，表建议。根据句意语境，本句是说妈妈不需要担心，故答案为B。 【点评】考查情态动词。理解句意并掌握情态动词的意义和用法区别。
一、选择题 1．(2017·甘肃白银·10)—I wonder if these are Danny's glasses. —They________be Danny's. He doesn't wear glasses. A．can't B．must C．mustn't D．can 2．(2018·山东临沂) Could you please speak a little louder? I ______ hear you very well. A．can’t B．mustn’t C．shouldn’t D．needn’t 3．Since you are very tired, you ______ finish the work today. A．needn’t B．may not C．mustn’t D．can’t 4．—Is Wendy in the classroom now? —I’m not sure. She ________ be there. I saw her in the library ten minutes ago. A．may not B．must not C．shall not D．would not 5．—Can I take some milk and biscuits to the reading room? —No, our school has a rule that students _______ eat or drink there. A．can’t B．mustn’t C．needn’t D．may not 6．—Tom, we’re going shopping at eight, right? —Yeah, but I ______ be a li ttle late, so don’t wait for me. A．may B．should C．mustn’t 7．You __ drive your car so fast. It's very dangerous. A．wouldn't B．shouldn't C．couldn't D．mightn't 8．—Susan, someone is waiting for you on the phone. It_______ be your sister, but I’m not sure.— Oh, please tell her to call me_______ because I’m busy now. A．might; later B．must; later C．might; late D．must; late 9．—The book report is very important. You ________ write it carefully. —But I ________ hand it in now. A．must; must B．have to; must C．must; have to D．have to; have to 10．You run with the train when it is coming. It’s dangerous. A．may not B．mustn’t C．needn’t 11．—I feel tired. —You ________ go to bed so late. A．must B．shouldn’t C．should 12．I’m sorry, children over 1.4 meters________pay t he full price for the show. A．may B．must C．can D．ought to 13．The flowers ________ every day, or they will die. A．must water B．can be watered C．should water D．must be watered 14．-_________ you help me with my homework?
一、选择题 1．—Look! Mrs. Smith is standing in front of the teaching building. —It______ her. She has gone to Egypt for her holiday. A．must be B．mustn’t be C．can be D．can’t be 2．—I’d like ________ Guo Jingming’s Tiny Times. —You had better________ his books. The stories he tells are far from real life. A．buying, don’t read B．to buy, not read C．buying, not read D．to buy, not to read 3．You have finished most of the work, so you ____ start working so early tomorrow. You may come at 9 :00. A．can't B．mustn't C．needn't D．couldn't 4．Since you are very tired, you ______ finish the work today. A．needn’t B．may not C．mustn’t D．can’t 5．All passengers_____ go through safety check before they take a plane. A．may B．can C．must D．need 6．A: Is Jim coming by train? B: I’m not sure. He _______ drive his car. A．must B．may C．need D．should 7．From March 23rd, 2013, anyone under the age of 14 ________ go into Disneyland alone. A．couldn’t B．mustn’t C．needn’t D．mightn’t 8．—Can I take some milk and biscuits to the reading room? —No, our school has a rule that students _______ eat or drink there. A．can’t B．mustn’t C．needn’t D．may not 9．— Mom, I got a big box from express(快递). What is it? —I’m not sure. It ________be a present from your grandmother. A．should B．might C．must D．will 10．—Have you heard about the temperature of the earth will rise to 59℃ in 2020?—Don’t worry! The news _______ be true. A．must not B．may not C．needn’t D．will not 11．He like coffee. I see him drink a cup at times. A．must B．may C．can’t D．mustn’t 12．Even the top student can't work out this problem, so it________ be too difficult. A．must B．may C．can D．need 13．—Jack must be in his office, I think. —No, he be in the office. He flew to Canada this morning. A．needn't B．shouldn't C．can't D．mustn't 14．It’s raining all day, so I ________ stay at home. A．can’t B．has to C．have to