情态动词
一、情态动词的基本用法
1.表示必须、一定。
must表示主观上的必须，而have to 表示职责或义务，强调客观。
In crowed places like airport and railway stations, you must take care of your
luggage.
There was no bus, so we had to go to school on foot.
2.表示推测或可能性
A.must表示推测仅用在肯定句中，must用于否定句时，表示禁止；can 或
could也可以表示推测, 其中can’t表示“不可能”；对过去的行为动作或状
态的推测用must/may/might/can’t/couldn’t+ have done
She is wearing a long face. She must be angry.
That can’t be my dad, he is now abroad.
B.may 或might 用于肯定句，might可能性较小，否定句可译作“可能不”。
You might just as well tell the manufacturer that the male customers may
not like the design of the furniture.
C.Should/ought to 表示推测时，是指有一定依据的推测、推论或可能性，意
为：可能、应该。
You should /ought to pass her chemistry final.
3.表示请求或许可
A.may 用于疑问句中表示询问许可，May I …答句是Yes, you may.否定句用
No, you mustn’t.还可以用can, could, might等表示许可。
May I use your eraser?
Yes, you may. /No, you mustn’t.
B.can表示许可时基本同may.
You can use my mobile phone on condition that you promise not to lend it
to others.
C.shall 用于第三人称可以表示向第二人称询问是否允许第三人称做某事。
Secretary: Shall he come in?
Manager: Let him in please.
4.表示必要
need 作为情态动词用于疑问句或否定句，Need you…?的肯定句答语是：Yes, I must.否定句的答语是：No, I needn’t/don’t have to.对问句Must…?
表示有必要做某事的肯定答语是：Yes, you must./you have to.否定句的答语是：No, you needn’t/don’t have to/don’t need to.
You needn’t come if you are busy.
You must finish the project by Friday.
5.表示能够
A.表示现在的或一般的能力用can 或be able to, can比be able to 更普遍，
be able to do 表示经过努力所具有的能力，有较多的时态变化。
A left-luggage office is a place where bags can be left for a short time,
especially at a railway station.
Are you able to type?
B.如果表示在过去某一待定的时刻经过努力终于做成了某事，用was/were
able to do sth.相当于managed to do sth或succeed in doing sth, 如果没有做成则可以用couldn’t 或wasn’t/weren’t able to do.
I was able to make her believe me.
6.表示建议或征求意见
A.shall 用于第一、三人称表征求意见或建议。
Shall we meet at the school gate tomorrow morning.
B.will 的疑问句表请求邀请
Will you lend me your eraser?
C.would 表示愿望、意愿、建议或看法。
a.表示强烈的愿望和意愿
“I would do anything for the soldiers.” said the boy.
b.表示请求语气时比will 委婉，并不表示过去意义。wouldn’t 表示请求、
邀请，没有否定的意思。
Wouldn’t you take a seat? 请坐。
c.would表示意愿，用在一些固定短语中，如：would like/would love to
do sth; would rather do sth.
I would like to have gone to the cinema, but I had an unexpected
visitor that evening.
D. had better 表示建议，意为：最好…强调现在或将来。
You’d better come early.
E. Could/might/would表示委婉的请求，肯定答语分别是can/may/will.
Could I sit here?
Of course, you can.
7.表示敢
dare作为情态动词时表示敢，用于疑问句或否定句；作为行为动词时同其
他动词一样用于各种句式，跟动词不定式作宾语，在疑问句和否定句中可
以省略to, I dare say是一个固定短语，意为“我认为、我相信”。
Tom daren’t go out alone when it is dark. (情态动词)
Tom doesn’t dare (to) go out alone when it is dark. (行为动词)
8.表示应该
should 表示义务、责任、命令、劝告，意为应该，ought to 表示义务、约束力、同should ,但是语气比should强，比must 弱，must意为应当做。
I should pay Tracy a visit, but I’m not sure whether I will have time this
Sunday.
Humans ought to stop polluting nature.
You must take the cost into consideration.
9.表示命令、警告、威胁
A.shall 与第二、三人称连用表示命令、许诺、警告、威胁等，表示说话人强
烈的意志.
You shall get an answer from me by tomorrow.
B.mustn’t是must 的否定形式，表示禁止，是一种命令、威胁或警告。
Tom, you mustn’t leave all your clothes on the floor like this!
10.表示惊讶、难以置信
A.should 用于疑问句中可以表示惊讶、难以置信的事情
Why should he tell a lie?
B.can用于疑问句或否定句可以表示惊讶、不相信等感情色彩。
How can you say that you really understand the whole story if you
have covered only part of the article?
11.表示宁愿
would rather意为宁愿，后跟动词原形，同used to, had better一样也被看
作是情态动词，有时称半情态动词。
She would rather work in the countryside.
12.表示偏偏
must可以表示偏偏，偏要，指不愉快的事。
After I gave her my advice, she must go and do the opposite.
二、情态动词+不定式完成时
1. must have done
表示对过去的事情肯定推测，意为：一定做过某事，只能用于肯定句。
It must have rained last night, for the road is all wet.
2. can’t/couldn’t have done
都可使用在疑问句和否定句中表示推测，可看做must表推测对应的否定形
式，can’t 比couldn’t的语气强，强调从现在角度出发推测过去某事的不可
能性, 但当主句的谓语动词为过去式时，表示假定或推断的从句必须用
couldn’t have done.
We knew he couldn’t have crossed the river, because the bridge was broken and there was no boat.
3. could have done
表示过去有能力或有可能做某事，而因某种原因未做，有惋惜、遗憾、批
评、责备的含义。
He could have passed the exam, but he was too careless.
4. should have done
表示本该做某事，而实际上没做，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意味。
I told your friend how to get to the hotel, but perhaps I should have driven
her there.
5. may/might have done
用于对过去的事情进行推测，表明说话人对过去可能发生的行为或存在的
状态的一种怀疑，might表达的可能性比may要小得多。如果主句的谓语动
词是过去时，从句必须用might have done.表某事本来可能发生，而实际上
未发生也只能用might have done.
You might have read about it in the papers.
6. need have done
表示本来需要做某事而没有做，needn’t have done 则表示本来不需要做某
事而做了。
I needn’t have taken the umbrella, for the weather is fine.
7. daren’t have done
用在否定句中表示过去本来不敢做某事，但是现在敢做了。
I daren’t have done it yesterday, but I think I dare now.
8. was/were would like to have done
表示本来打算做某事但是却干了别的事。
I would like to have gone to the party last night but I had to work extra
hours to finish a report.
9. would have done
虚拟语气，表示对过去事情的假设，意为：本来会做。
I would have told you all about the boy’s story, but you didn’t ask me.
形容词和副词的比较等级
1.同级比较
A.双方比较程度相同的时候，用as+形容词或副词的原级+as 这一结构。
I think physics is as important as maths.
B.双方比较程度不同等时，用 not+as/so +形容词或副词的原级+as这
一结构。
It is not as/so warm today as yesterday.
C.当同级比较的形容词与单数可数名词连用时，应注意不定冠词的位置，
通常为：as+形容词+a/an+单数名词+as 这一结构。
Would you like to join us?
Sorry, I’m not so good a player as any of you.
2.比较级
A．比较双方中一方超过另一方的时候，要用形容词/副词的比较级
+than+比较对象这一结构。
Zhang Hua is taller than Wang Ping.
B. 表示…不如…用less+原级+than 这一结构。
The film is less interesting than that one.
C. 除比较句中与than连用表示比较之外，下面的词语后面必须用to构
成比较，常用的词有inferior, superior, junior, senior, prior.
He is superior to Mr. Wang in English.
D. 表示两个人/物之间比较…的，用the +比较级+n+of+the+名词/代词
这一结构。
She is the taller of the two girls.
E. 表示越来越…用形容词比较级+and+ 形容词的比较级； the+形容词/
副词比较级，the +形容词/副词比较级。
It turned warmer and warmer.
The harder he works, the more progress he has made.
F. 表示几倍于…时，用倍数+as…as或倍数+比较级+than…
Our classroom is three times larger than yours.
G. 形容词比较等级前可以用much, very much, even, still, far等来修饰，
表示比较的程度。
Tom’s handwriting is far better than John’s.
H. 其他含有比较级的短语和句式
more…than…与其说…倒不如…
more or less 几乎、大约
more than 多于
less than 少于
sooner or later 迟早、早晚
what’s more 而且
no sooner than…一…就…
not more than=at most 至多，不超过
no more than=only 仅仅、只不过
no less than =as many as 有…之多
not less than =not fewer than 不少于
3. 最高级
A. 表示三者或三者以上的人或物相比的时候，其中一个人或物在某方面
比其他的都强，这就要用到形容词和副词的最高级，the +形容词或副
词的最高级+其他+of/in/among(比较范围)，意为…中最…。
Zhang Hua is the tallest of the three.
He works the hardest in our class.
B. 最高级也可被序数词及much, by far, nearly, almost, nothing like等
词来修饰。
This hat is nothing like the biggest.
注意：
高中英语情态动词精讲与解析 概说 助动词(auxiliary)主要有两类：基本助动词(primary auxiliary)和情态助动词(modal auxiliary)。基本助动词有三个：do, have和be；情态助动词有十三个：may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to. 上述两类助动词的共同特征是，在协助主动词构成限定动词词组时，具有作用词的功能： 1）构成否定式： He didn't go and neither did she. The meeting might not start until 5 o'clock. 2）构成疑问式或附加疑问式： Must you leave right now? You have been learning French for 5 years, haven't you? 3）构成修辞倒装： Nowhere can he obtain any information about his sister. Hardly had he arrived when she started complaining. 4）代替限定动词词组： A: Who can solve this crossword puzzle? B: Tom can. A: Shall I write to him? B: Yes, do. 情态助动词的特征 基本助动词与情态助动词最主要的区别之一是，基本助动词本身没有词义，而情态助动词则有自己的词义，能表示说话人对有关动作或状态的看法，或表示主观设想： What have you been doing since? （构成完成进行体，本身无词义） I am afraid I must be going. （一定要） You may have read some account of the matter. （或许已经） 除此之外，情态助动词还有如下词法和句法特征： 1）除ought和used以外，其他情态动词后面只能接不带to的不定式。如果我们把ought
情态动词的用法 A. can; could; be able to Can 1. 表示“能力”(此时过去时是could) 2.表示许可、请求，“可以”。--Can/Could I go now? 3 表示推测, 把握很大,could也可表推测,把握比can小。 --Look! Someone is coming! Who can it be? --It can?t be him. He has gone to Paris.（不可能）/ He could be here soon. 他很快就来。 4 表示感情（惊异/不耐烦）“究竟，到底”（主要用于否定句，疑问句和感叹句中。） How can you be so foolish? What can it possibly be? 到底那是怎么一回事? They can?t be working at this time of day. 5 肯定句中客观存在的可能性。“有时会，偶尔” It can be quite windy there, especially in spring. Could 1.表示能力，can 的过去式，过去能够 Could you speak English then? 那时候你会说英语吗? 2. 请求允许（委婉语气）（问句的答语不用could，而用can，） Could [Can] I use your pen? ” “Yes, of course you can.”/ No, I?m afraid not. 3. 表示推测可能性（肯，否，疑） We could go there this summer. 今年夏天我们可能要去那儿。(将来可能性) You could be right, but I don?t think you are. 你可能是对的，但我并不认为你是对的。 4. could have done ①对过去推测，可能已经。。。②本来能够却没做，差点就 He can?t [couldn?t] have seen her there. 他不可能在那儿见到她。 He could have gone home. 他可能已回家了 He could have told her, but he didn?t choose to. 他本来可以告诉她的，但他却没有。 B. may 和might 1.表示允许﹑许可，might提问更委婉。 ---May/Might I watch TV after supper? ---Yes, you may./ Yes, please./ Certainly. ---No, you mustn't. / No, you may not. / No, you can?t./No, you?d better not. 2. 表示推测，有“或许”、“可能”的意思。might把握更小。疑问句用can/ could. ?He may/might be right./ I hear there may be a few copies left. ?He may/might come today (tomorrow). 3. may表示祝愿，倒装。May +主语+动词原形。May you succeed!/May you all be happy. ☆may [might] as well…意为“不妨”、“还是…为好”等，用might 比用may 语气更委婉。如：I?m ready，so I might as well go now．我已准备好，因此不妨现在就走。 There?s nothi ng to do, so I may [might] as well go to bed. ☆may well... 完全可能 C. must, have to Must 1. 表示“必须”。否定式mustn?t表示“不可以”、“不准”、“禁止”等。 Everybody must obey the rules../You mustn?t lend it to others./You mustn?t speak like that to your mother. ☆在回答有“must” 的询问时，--- Must I go now? --- Yes, you must. ---No, you needn?t. / No, you don?t have to.
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。
情态动词专项练习（一） 1. I __________ you, because I thought I must be wrong. A. dare not ask B. dare not to ask C. dare not asking D. dare to not ask 2. There __________ some flowers in the garden. A. were used to be B. used to be C. uses to be D. used to be having 3. ―__________ I take it out?‖―I′m sorry, you __________.‖ A. Could …couldn′t B. Might…might not C. Could…can D. May…can′t 4. You were stupid to climb the tree. You __________ hurt yourself. A. may B. might C. will D. might have 5. You __________ those letters. Why didn′t you ? A. should post B. should have posted C. must have posted D. ought to post. 6. All the lights are on, the Smiths __________ up. A. must get B. is getting C. must be getting D. would get 7. He __________ lead a horse to the water but he __________ not make it drink. A. will…can B. may…can C. may…dares D. dare…can 8. ―Need we do this job now?‖―Yes,__________.‖ A. you need B. you should C. you must D. you can 9. __________ to have lunch with us today? A. Do you likes B. Would you like C. Will you liked D. Have you liked 10. He said that you __________ watch TV all the evening if you wished. A. may B. must C. can D. might 11. –Is John coming by train? --He should, but he __________ not. He likes driving his car. A. must B. can C. need D. may 12. Peter __________ come with us tonight, but he isn′t very sure yet. A. must B. can C. may D. will 13. Michael __________ be a policeman, for he′s much too short. A. needn′t B. can′t C. shouldn′t D. won′t 14. I thought you __________ be hungry, so I have brought you some cakes. A. may B. might C. can D. could 15. I wonder how he __________ that to the teacher. A. dare to say B. dare saying C. not dare say D. dared say 16. Come on! We __________ hurry because there isn′t much time left. A. may B. must C. can D. need 17. Amy did best in the English test. She __________ hard last week. A. must have working B. should have worked C. should work D. must work 18. The fire spread through the hotel very quickly but everyone __________ get out. A. had to B. would C. could D. was able to 19. –--I stayed at a hotel while in New York. ---Oh, did you? You __________ with Barbara. A. could have stayed B. could stay C. would stay D. must have stayed 20. It′s nearly seven o′clock. Jack __________ be here at any moment. A. must B. need C. should D. can 专项练习（二） 1. Jean have kept his promise. I wonder why he changed his idea. A. must B. should C. need D. would
高中英语情态动词详解 1. 表示请求和允许: can，could ，may，might. 过去式使语气更委婉，答语应用原形。 --- Could I use your computer tomorrow morning? --- Yes，you can.( 否定回答可用：No，I’m afraid not.) 1)can表示理论上的可能性，指某事或情况可能发生，但并不说明实际上真的发生. Children can be very tiring. 2)对现在事情的推测：情态动词+do 对过去事情的推测：情态动词+have done 对已完成事情的推测：情态动词+have done 3)反意问句： He may know the plan，doesn’t he? You must have studied English before，haven’t you? You can’ t have been caught in the rain last night，were you? 3．can & be able to 在肯定句中can表示有“能力”做，be able to表示通过想办法/努力等而能够做成了某一件事，相当于managed to do…或succeeded in doing sth. Birds can fly. The fire spread through the hotel very quickly but everyone was able to get out. 4. may / might as well do sth“还是…好”、“不妨” You might as well tell me the truth. 你还是把真相告诉我的好。 5. must和have to 1) must表示的是说话人的主观看法，而have to强调客观需要。 2）否定形式含义不同。mustn’t禁止，不许可，don’t have to不必 3) must 偏要（做令人不快的事）eg. Must you shout so loudly? 6. shall和should 1)表示说话人征求对方意见和向对方请示，用于第一、三人称。 When shall my father be able to leave hospital? Shall2) 用于第一、三人称2) 用于第二、三人称，表示说话人给对方的命令、警告、允诺或威胁以及说话人的决心。 You shall go with me (命令)/ You shall have the book when I finish it.33（允诺） He shall be punished （威胁）/ Nothing shall stop me from doing it. (决心)
高中英语情态动词用法归纳与练习 A: can / could = be able to 1 表示能力两种时态can (could)，其他时态要用be able to的形式 He can speak French. Was/were able to 可以表示成功做成某事的含义* managed to do / succeeded i n doing With our help, he was able to build the house. 2 表示请求或许可Could 比Can 更加客气* may Can I go now? Yes, you can. 3 表示推测或可能性，常用于否定句和疑问句 Can he be at school? Today is Sunday. He can't be at school. Can’t couldn’t/ Can ? Could? have done There is no light in the room. Can she have gone to bed? She can’t have gone to school----- it’s Sunda y. Could have done 可用在肯定句中表示过去存在的可能性* may have done She could have gone out with some friends yesterday. Could have done 可以表示虚拟语气 某事可能发生（并没有发生） It was silly to throw the TV out of the window. It could have hit somebody. 批评某人没有完成某事(本可以做某事) You are late again. You could have got up earlier. 4 can 表示客观上的可能性* Anybody can make mistakes. B: may and might 1 表示请求和允许类似用法can could(更加口语化) May I watch TV now? Yes, you may. 2 表示可能性; 猜测might比may更加不确定may/might have done 对过去的揣测* He may be busy these days. May not 可能不；不可能；一定不可 3 表示祝愿Wish you success! May you succeed!* C: must and have to 1 表示必须；一定要可以用have to 代替 must 现在；将来的必须而且是主观看法* have to 有多种时态而且强调客观情况 I really must stop smoking now. I had to leave early because I wasn’t feeling well. Must I come here?
高考情态动词(完整版) 一、单项选择情态动词 1．Look! There are so many mistakes in your composition. You ________ have fixed full attention on it. A．can B．should C．need D．might 【答案】B 【解析】 【详解】 考查情态动词。句意：看！你的作文里有那么多的错误。你本应该把所有的注意力都集中在它上面的。表示“本应该做但实际上没有做”应该用should have done结构，can have done 表示可能；need表示需要；might have done表示可能做过某事；故选B。 2．Most of the top leaders expressed a common desire at the UN conference, ______ that different cultures ______ coexist with tolerance. A．the one ; must B．the one ; should C．one ; must D．one ; should 【答案】D 【解析】 【详解】 考查替代和情态动词。句意：大多数高层领导人在联合国大会上表达了一个共同的愿望，即不同的文化应该与宽容共存。大多数高层领导人在联合国大会上表达了一个共同的愿望，即不同的文化应该与宽容共存。替代表泛指的单数名词，通常用one替代。此处用one替代前面的a desire，是同位语；结合句意第二空用情态动词should“应该”。故选D。【点睛】 that ,it ,one 代指前面的名词时的用法 1.one 指代前面出现的可数名词，是泛指。可以和冠词连用，也可以有自己的定语。一般不能用做特指，但和定冠词连用时可以是特指。如： Please show me the cup, the red one on the shelf. 2.It 指代前面提到的单数名词，相当于the one。当one是泛指的时候，指的是同名异物，it是指同一物体.如： ----Do you want the cup ? ---Yes ,I want it. 3.that通常用来代替前面出现的可数名词\不可数名词,主要是用来避免重复。如： The weather of Guangzhou is hotter than that of Beijing. 3．Paul did a great job in the speech contest. He many times last week. A．need have practised B．might practise C．must have practised D．could practise 【答案】C 【解析】
情态动词 情态动词是高考考查的重点语法项目之一，2005年全国17套高考试题对此都有考查。下面就近几年来高考试题中出现的情态动词的考点进行归纳分析，以便同学们复习掌握。 一、情态动词表推测 1. 肯定的推测一般用must, should, may（might）或could（不用can），其中，must的语气最强，译为“肯定”、“准是”、“想必是”；should的语气次之，译为“很可能”、“应该”，指按常理推测；may（might），could的语气最弱，译为“也许”、“可能”。 ①Helen _______ go on the trip with us but she isn’t quite sure yet. （2005年安徽卷） A. shall B. must C. may D. can ②—I’ve taken someone else’s green sweater by mistake. —It ___ Harry’s. He always wears green. （2005年广东卷） A. has to be B. will be C. mustn’t be D. could be ③I have lost one of my gloves. I _______ it somewhere.（2005年北京春季卷） A. must drop B. must have dropped C. must be dropping D. must have been dropped ④If I ____ plan to do anything I wanted to ,I’d like to go to Tibet and travel through as much of it as possible. （2005年湖北卷） A. would B. could C. had to D. ought to 2. 否定推测分为两种情况： 1）语气不很肯定时，常用may not, might not或could not，译为“可能不”、“也许不”。 You might just as well tell the manufacturer that male customers ______ not like the design of the furniture. （2004年上海春季卷） A. must B. shall C. may D. need 2）否定语气较强时，则用can’t，译为“根本不可能”、“想必不会”，表示惊异、怀疑的感情色彩。 ①—Do you know where David is? I couldn’t find him anywhere. —Well. He ______ have gone far——his coat’s still here.（2005年湖北卷） A. shouldn’t B. mustn’t C. can’t D. wouldn’t ②— Isn’t that Ann’s husband over there? — No, it _______ be him I’m sure he doesn’t wear glasses. （2004年全国卷Ⅰ） A. can’t B. must not C. won’t D. may not 3. 疑问句中的推测，往往用can或could。 Mr. Bush is on time for everything. How ______ it be that he was late for the opening ceremony？（2001年上海春季卷） A. can B. should C. may D. must 4. 对已发生事情的肯定推测常用“must, may, might等+完成式”；否定推测常用“can, could, may, might等+完成式”。 ①I was on the highway when this car went past followed by a police car. They _______ at least 150 kilometers an hour.（2005年重庆卷） A. should have been doing B. must have been doing C. could have done D. would have done ②He _______ have completed his work; otherwise, he wouldn’t be enjoying himself by seaside. （2005年北京卷）
英语情态动词用法详解 一、单项选择情态动词 1．Look! There are so many mistakes in your composition. You ________ have fixed full attention on it. A．can B．should C．need D．might 【答案】B 【解析】 【详解】 考查情态动词。句意：看！你的作文里有那么多的错误。你本应该把所有的注意力都集中在它上面的。表示“本应该做但实际上没有做”应该用should have done结构，can have done 表示可能；need表示需要；might have done表示可能做过某事；故选B。 2．---Hi, Johnson, any idea where Susan is? ---It is class time, so she __________ in the classroom now. A．can be B．must have been C．might have been D．should be 【答案】D 【解析】 考查情态动词的用法。A. can be可能，可以是；B. must have been一定（对过去事实肯定的推测）；C. might have been可能（对过去事实肯定的推测）；D. should be应该是。句意：—知道苏珊在哪里吗？—现在是上课时间，她应该在教室里。故答案选D。 3．The room is so clean. He ________ have cleaned it yesterday evening. A．will B．need C．can D．must 【答案】D 【解析】 【详解】 考查情态动词表推测。句意：房间如此干净，他一定是昨天晚上打扫过了。must have done 表示对过去发生的事情有把握的猜测，意思是“一定（做过）”，故D项正确。 4．— Excuse me, do you mind if I open the window? — Well, if you __________. I can put on more clothes. A．can B．may C．must D．shall 【答案】C 【解析】
情态动词专项讲解 1. China is developing its high-speed train technology fast, so it _____be good enough to catch up with the best. A. may B. might C. must D. should 2. Then some other interesting reasons appear, such as “It's so smoggy that I ______find my way to office." A. mustn’t B. won’t C. can’t D. shouldn’t 3. "The world is big, and I want to see it," wrote a teacher in her resignation letter. _____ you quit your job to travel the world A. Must B. Might C. Should D. Would 【答案揭晓】CCD 一、情态动词的定义 情态动词是一种本身有一定的词义，但要与动词原形或其被动语态一起使用，给 谓语动词增添情态色彩，表示说话人对有关行为或事物的态度和看法，认为其可 能.应该或必要等。情态动词后面加动词原形。 1. No driving electric motorbikes in some areas is a rule that we shall obey in Fuzhou.
必须.一定（法律.法规等）动 词原形 2. Women who are exposed to second-hand smoke during their pregnancy can be at risk of abortion.能，会，可以(表示有能力或机会) 动词原形 二、常考情态动词的关键用法 (一) can 1. －Jim，it is time you went to bed．You need to get up early tomorrow. －It’s not f air，Mary can stay up till ten hut I have to go to bed at eight. 可以(表示允许) it were not for the fact that she can't sing，I would invite her to the party. 能，会，可以(表示有能力) 3. Luckily, iron can be reworked and mistakes don't have to be thrown away 能够，可以(表示某事物的特点) can be really difficult to get along with at times even though he’s a
高考英语情态动词讲解标准化管理处编码[BBX968T-XBB8968-NNJ668-MM9N]
（一）情态动词常考点 （一）表能力 如：I am starving to death。I can eat two bowls of rice now。 （现在的能力）我快饿死了，现在我能吃两碗米饭。 If you have a good sleep，you will be able to work out this problem。 （将来的能力）如果你好好睡一觉，你将能够解出这道题。 The fire spread through the hotel very quickly but everyone was able to get out。 （过去有能力做并且成功的做了某事）尽管这场大火迅速蔓延到了整个宾馆，但是每个人都能够逃出去。 I could have worked out the problem，but I didn’t。 （过去有能力做但未做）我本来可以解决这个问题，但没有解决。 （二）表推测（可能性） 1.可能性可分为客观的可能性和具体事情实际发生的可能性两种。所谓客观的（理论的）可能性即并不涉及具体某事是否会发生，此种用法常常可以说明人或事物的特征。情态动词can可用于肯定句中表示客观的（理论的）可能性，而表示具体事情实际发生的可能性时，can一般不用于肯定句。如：
（2）表示具体事情实际发生的可能性时，may，must常用于肯定句，一般不用于否定句和疑问句（may not表示“可能不”）；can常用于否定句、疑问句或感叹句中，表示疑惑、惊讶或不相信等意思；could既可用于肯定句，又可用于否定句、疑问句中。如： This can’t/ couldn’t be done by him。（表不相信） 这不可能是他做的。 This may not be done by him。（表不确定） 这可能不是他做的。 He could be on his way home now。（could不如may/ might常用）
一、情态动词无人称和数的变化，不能单独做谓语，只能和行为动词或状态动词构成谓语 二、情态动词分为：情态助动词：can(could)、may(might)、must、have to (had to )、ought to 、 shall(should)、will(would) 12个 半情态助动词：dare、need、used to、had better、would better(5个) 三、情态助动词 1.can and could 1)ability：be able to do /manage to do/succeed in doing sth. eg.The army can defeat their enemy. eg.The army is able to defeat their enemy. eg.The army succeed in defeating their enemy. 2)permission:eg.Can I smoke here? eg.You can’t smoke here. 3)possibility:用在否定句、疑问句、感叹句中- eg.This can’t be done by him. 当被用在肯定句中时，表达的是理论上的可能性，不涉及是否真的会发生 eg.even expert drives can make mistakes. 要表达现在或者将来的可能性，用may /might或could. eg.I may leave for Beijing next month. 但在特殊疑问句中，或与副词hardly、only等连用的陈述句中表达可能 性只用can/could Eg.where can the noise be coming from? eg.It can hardly be the postman,he comes only in the morning. 4)有时会：the road can be blocked. 5)could 表示轻微的怀疑或委婉的看法 I’m sorry I couldn’t lend you the book now. His story could be true,but I hardly think it is. 6)could 表示委婉的请求，主要用于疑问句，不用于肯定句 Could you lend me some money? Yes,I can /No,I am afraid not. 7)could 的常用结构：could+动词+比较级“非常，再.....不过了” It couldn’t be better. Couldn’t +过去分词+比较级“非常，再.....不过了” They couldn’t have tried harder to make me eel welcome. Can’t..too..=can never too“无论怎样...也不为过,越...越好” I can’t thank you too much.I owe my progress to you. Can’t (help/choose) but do/can but +动词原形“不得不，只好” We can but agree with him. Can’t help doing 忍不住，不得不 I can’t help laughing Can’t be (it) 控制不住，没有办法 It can’t be helped Can’t....without 没有...就不能 One can’t succeed without perseverance.
高中英语语法总结大全之情态动词情态动词的语法特征 1) 情态动词不能表示正在发生或已经发生的事情,只表示期待或估计某事的发生。 ２）情态动词除oｕgｈt和have外,后面只能接不带to 的不定式。 3）情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。 4）情态动词没有非谓语形式，即没有不定式，分词，等形式。 比较can 和be aｂlｅto １)cancould 表示能力；可能(过去时用ｃould)， 只用于现在式和过去式（ｃould)。be ａble ｔｏ可以用于各种时态。 Tｈey will ｂe aｂlｅｔo ｔeｌｌyou tｈe ｎews ｓｏon．他很快就能告诉你消息了。 ２）只用bｅablｅto a. 位于助动词后。 b.情态动词后。 c．表示过去某时刻动作时。 d. 用于句首表示条件。 ｅ. 表示成功地做了某事时,只能用wａs/were able to, 不能用cｏuld。 Ｈeｗas ablｅto ｆlee Eurｏpｅbefｏre tｈeｗar broｋe ｏut. =He ｍaｎａgeｄtｏfｌee Euroｐeｂefore thｅwar broke out. 注意:could不表示时态 1)提出委婉的请求，(注意在回答中不可用cｏｕｌd)。 ---CoulｄI haｖe tｈｅtｅlｅｖiｓioｎon? --－Yes,ｙou ｃan. / Nｏ，you can'ｔ. 2）在否定,疑问句中表示推测或怀疑。 Hｅcouldn't be a bａd ｍaｎ. 他不大可能是坏人。
比较ｍay和might 1）表示允许或请求;表示没有把握的推测;mａｙ放在句首,表示祝愿。 May Gｏd bｌｅss yｏu！ Ｈｅmiｇht be aｔhome． 注意：might 表示推测时,不表示时态。只是可能性比may 小。 2) 成语: may/might as well,后面接不带to 的不定式，意为"不妨"。 Ifｔhａt is thｅcase, we may ａs ｗell try. 典型例题 Ｐetｅｒ_＿＿come wｉｔh us tonighｔ，but ｈe iｓn't ｖery sｕrｅyet. A. mｕstB．ｍayC. canD. wｉll 答案Ｂ. 表可能性只能用may.此句意可从后半句推出。 比较hａｖe ｔo和mｕst 1)两词都是＇必须＇的意思，ｈave tｏ表示客观的需要，ｍｕｓｔ表示说话人主观上的看法，既主观上的必要。 My ｂroｔher ｗas ｖery ilｌ, ｓo Ｉhａd toｃaｌl tｈe docｔｏr iｎtｈｅmiddlｅof tｈｅniｇhｔ.我弟弟病得很厉害，我只得半夜里把医生请来。(客观上需要做这件事） He said that theyｍust wｏrｋｈａrd．他说他们必须努力工作。(主观上要做这件事) 2)hａve to有人称、数、时态的变化,而must只有一种形式。但must 可用于间接引语中表示过去的必要或义务。 Hｅｈaｄtｏlｏok after ｈｉｓｓisterｙｅsｔerday． 3) 在否定结构中：dｏn＇t hａvｅto表示"不必" mustｎ＇t表示"禁止"， You ｄｏn'ｔhａvｅto tell hiｍabout iｔ．你不一定要把此事告诉他。 Ｙｏu mustn＇ｔｔｅlｌhim aboｕt ｉt.你一定不要把这件事告诉他。 must表示推测 1)muｓｔ用在肯定句中表示较有把握的推测，意为"一定＂。