初中英语情态动词知识点及经典练习题
情态动词知识点总结:
(一)情态动词的定义????情态动词表示说话人对动作的态度,比如:需要,可能,意愿,猜测或者怀疑等等。(二)情态动词的特点??1)有一定词义;
2)不受主语人称和数的变化影响;
3)与主要动词的原形(或称不带to的不定式)一起构成谓语(除ought to作固定词组看待)。 4)否定句中,在情态动词后面加not。
(三)情态动词有:must, shall, should, had better 词形无变化
can(could), may(might), will(would) 词形有变化
need既可以是情态动词,也可以是实义动词,具有双重性。
(四)情态动词的基本用法1. can (could)
1)表示会做某事,有能力做某事。意思 = be able to 其否定式can’t表示“不能”。在过去时中用could和couldn’t. (即有种能力,尤其是生来具备的能力,此时may和must均不可代替它)。
He can speak English, but he can’t speak Japanese.
= He is able to speak English, but he isn’t able to speak Japanese.
I could smile but I couldn’t speak when I was 2 months old.
= I was able to smile but I wans’t able to speak when I was 2 months old.
区别:1、 can只用于现在时和过去时(could), be able to 可用于各种时态。
They will be able to tell you the news soon.
2、be able to 不与can连用,但可以和其他情态动词或助动词连用。
He may be able to speak English very well some day in the future.
3、用在过去时中,could经常表示能够做某事,事实上不一定去做,而was∕were able to则表示“过去做成了某事”。在否定句中两者可通用。
2)用于征求意见
——Can /Could /May /Might I(we) do sth?
——Yes, you can/may. / Of course you can.
——No(Sorry), you can’t. /mustn’t.
注意:①此处的could和might都不表示过去,只是语气上的委婉,不用作回答。
②否定回答中,表示对他人造成一定伤害或影响,或表示违反了某种规定或法律时,用mustn’t较好。
e.g. ——Could I take the book out of the library? ——Sorry, you mustn’t.
——May I smoke here? ——I’m afraid you mustn’t.
③表示过去能力时,could 提问,只能用could回答。
e.g. ——Could you ride a bike when you were 4 years old? ——No, I couldn’t.
3)表提出意见或请求
Can/Could you (please) do sth? = Would you (please) do sth? (此句型中some 不变any)
e.g. Could you please give me a hand?
Would you please pass me some salt?
4)表示允许或承诺 =may
e.g. OK. You can /may come and find me at any time tomorrow.
5)表示有一定把握的推测,用于否定句和疑问句。此时can’t译为“不可能” 肯定句用must。表示没有把握的推测,用may /might。
e.g. —— The window is broken. Who did it?
—— It may be Mary.
—— It can’t be Mary. The window is in the men’s toilet.
—— Can it be anyone else?
—— Then, it must be Bob. I saw him go into the toilet just now.
He can’t (couldn’t) have enough money for a new car.?? 他不可能有足够的钱买新车。【例题】—I think Miss Gao must be in the library. She said she would go there.—No. She __be there, I have just been there. A.can’t B.mustn’t C.needn’t D.wouldn’t
【解析】根据下文“我刚去过那儿”可知,应为“不可能”,can’t表示推测[答案] A
2. may (might)
may 表示“可以,可能”,否定形式may not,表示“不可以”。
1) 表示没有把握的推测,“可能,也许”。可以指过去时间,也可以指现在时间,但语气更加不肯定。
e.g. He may have a lot of work to do. = Maybe he has a lot of work to do.
You may be right. = Maybe you are right.
2)表示请求 “我可以……吗?” 表示请求、许可,比can正式
e.g. You may /can go now.
——May I use your pen?
——Yes, you may. / Yes, please. / Go ahead.
——No, you can’t. / mustn’t.
在回答以may引起的问句时,多避免用这个词,而用其它方式,如Yes, please. / Certainly. / Please don’t ./ You’d better not. / No, you mustn’t.等,以免显得太严峻或不客气。3)、 表示希望、祈求、祝愿,常可译为“祝愿”。通常是用may +主+V例如:May you have a good time.祝你过得愉快。May you be happy!祝你幸福!May you succeed!祝你成功!
3. must
must 表示“必须,肯定,一定”, 否定形式mustn’t = must not表示“禁止”。
1)表示必须,意思同have to
e.g. ——Must I do it now?
——Yes, you must.
——No, you don’t have to. / No, you needn’t. (注意:否定回答不用mustn’t)
Children mustn’t play on the road because it’s too dangerous. (mustn’t只表“禁止”)
He doesn’t have to go away from here.
=He needn’t leave here.
区别:①must表达主观意愿的“必须”,have to表达客观上或按道理说“不得不”。
e.g. I must study hard.
It’s too late. I have to go now.
②must 没有人称和时态的变化,而have to有。
e.g. He had to walk back home because he lost all his money.
Mom will be away for a week, so we will have to do the cooking by ourselves.
2)表示有把握的肯定句中的推测,“肯定,一定”,只用于肯定句。He must be ill. He looks so pale.?? 他准是病了。他的脸色苍白。
注意其反意问句的构成形式:
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。如:
She must have seen the film before,hasn’tshe?(注意反意疑问句的后半部分)
You must have met uncle Wang in the shop yesterday,didn’t you? (注意反意疑问句的后半部分)
4.need
need 表示“需要”,否定形式needn’t = need not “不必、不需要”
1)、作情态动词,仅用于否定句和疑问句。
e.g. He needn’t go home early yesterday. = He didn’t need/have to go home early yesterday.
Need I call him right now? ——Yes, you must.(注意:肯定回答不用need)
——No, you needn’t. /No, you don’t have to.
2)、作实义动词,此时有人称、数和时态的变化,如果是人作主语后边多接动词不定式:need sth./sb.
need to do sth. 否定形式don’t need to = don’t have to 表示“不必”
e.g. I need some help.
He needed to go home early yesterday.
Do I need to call him right now? ——Yes, you do. / ——No, you don’t.
如果是物作主语,一般用need doing与need to be done这种情况下应注意两点:
①.主动形式的动名词doing具有被动的含义;②.该动名词可以改为其动词不定式的被动形式而句子的意义不变。例如:. The door needs painting. = The door needs to be painted.那扇门需要油漆一下。Your car needs mending. = Your car needs to be repaired.你的车需要维修了。
3)、 need 作名词
be in (great) need of sth = need sth (badly) “非常需要某物”
meet the need “满足需要(需求)”
there is/was no need (for sb) to do sth “某人没必要做某事”
5. 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。如:Dare he tell them what he knows?他敢告诉他们所知道的情况吗?I daren’t ask her – will you do it for me?我可不敢问她,你能帮我问问吗?
(2)dare作为实义动词,此时有人称、数及时态的变化。如:He doesn’t dare to break his promise.他不敢食言。
注意:在口语中,dare的各种形式常与不带to的不定式连用。如:Do you dare tell her what I said?
你敢告诉她我说的话吗?I didn’t dare look at him.我不敢看他
归纳:need和dare的用法????1、need和dare既可用作情态动词,也可用作实义动词。用作情态动词时,通常不用于肯定句而主要用于否定句和疑问句。用作实义动词时,可用于各种句式。 2、其他用法:I dare say…为固定习语,不是“我敢说”而是“我想”。
I dare day he’ll come again.?? 我想他会再来的。
Needn’t have done:表示本没必要做而做了
6. shall的用法:
1)表征询意见,用于第一、第三人称疑问句。Shall I get some tea??? 我给你点茶好吗?Shall the boy wait outside???让那男孩在外面等吗?2)表说话人的意愿,有“命令、允诺、警告、决心”等意思,用于第二、第三人称陈述句。You shall do as I say.?? 按我说的做。(命令)You shall have my answer tomorrow.?? 你明天可以得到我的答复。(允诺)He shall be sorry for it one day, I tell you.?? 有一天他会后悔的,我告诉你。(警告)Nothing shall stop us from carrying out the plan.??什么也不能阻止我们执行这项计划。(决心)
归纳:在英语中,我们可以用其他多种方式提出我们的建议或征求对方意见。
(1).用“Let's do...”来提出建议。如:Let's go for a walk after supper.
(2).用“What/How about...?”来提出建议;about后接名词或动词ing形式。如:What about/How about a drink? What about/How about taking Tom with us?
(3).用“Why not...?”来提出建议,表示“何不……”not面后接动词原形。“Why not...?”实际上是“Why don't you/we...?”的简略形式。如:Why not meet at the school gate at eight? Why don't we stay here another day?
(4).用“Would you like...?”来提出建议,意思是“你想要……吗?”Would you like后可接名词或不定式。如:Would you like a cup of tea? Would you like to go and see her?
因此,如果我们说:“去游泳好吗?”英语中可有这样几种表达法:Shall we go for a swim? Let's go for a swim,shall we? What about/How about going swimming? Why not go for a swim? Would you like to go for a swim? What do you think of going for a swim?
6、 will的用法1)、表意愿,用于各种人称陈述句。“愿意”I will do anything for you.?? 我愿为你做任何事。2)、表请求,用于疑问句。Will you close the window? It’s a bit cold.?? 请你把窗户关上好吗?有点冷。Won’t you drink some more coffee??? 再来一点咖啡好吗?
注意:
1、will在there be句型中的形式及其句式变换。
由于“一般将来时”的结构可以用“will+动词原形”来表示,所以there be句型的一般将来时的形式就是there will be。(一定不能说there will have)例如:There are many students in our school.→There will be many students in our school. There will be a sports meeting next week.一定不能说:There will have a sports meeting next week.
2、will与be going to do something区别:
①. be going to表示近期、眼下就要发生的事情,will表示的将来时间则较远一些,如:He is going to write a letter tonight. He will write a book one day.
②. be going to表示根据主观判断将来肯定发生的事情,will表示客观上将来势必发生的事情。He is seriously ill. He is going to die. He will be twenty years old.
③. be going to含有“计划,准备”的意思,而will则没有这个意思,如:She is going to lend us her book.
He will be here in half an hour.
④.在有条件从句的主句中,一般不用be going to,而多用will,如:If any beasts comes at you, I'll stay with you and help you.
7. should的用法
1)、表义务。意为“应该”(某件事宜于做),用于各种人称。否定形式 shouldn’t = should not表示“不应该”You should be polite to your teachers.?? 你对老师应该有礼貌。2)、表推测,意为“想必一定、照说应该、估计”等。The film should be very good as it is starring first-class actors.?? 这部新电影是一流演员主演的,估计拍得很好。They should be home by now.?? 照说他们现在应当已经到家了。
8.would的用法1)表意愿I said I would do anything for you.?? 我说过我愿意为你做任何事。2)表委婉地提出请求、建议或看法。常见句型:①表请求Would you please do…? ——OK…. / Sorry, ….
②Would you like sth? ——Yes, please. / No, thanks.
Would you like to do sth? ——I’d love to.
——I’d love to, but….
(注意:以上句型中,some不变any)
9. ought to 1)表义务,意为“应该”(因责任、义务等该做),口气比should稍重。You oughtn’t to smoke so much.?? 你不应该抽这么多烟。2)表推测,暗含很大的可能,语气较弱。There’s a fine sunset; it ought to be a fine day tomorrow.??今天有晚霞,明天应该是个好天。
10、used to 表示过去的习惯动作或状态,现在不复发生或存在。疑问式和否定式有两种。I usedn’t (didn’t use) to smoke.?? 我过去不抽烟。Used you (Did you use) to go to school on foot??? 你过去常步行去学校吗?
11、had better do表示“最好是做……”,否定形式 had better not do
e.g. You’d better not drink so much coffee.
区别:It’s better for you to do more exercise and not to have so much junk foo
归纳:一、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,如:He can’t be ill. He is playing chess with Tom.他不可能病了,他正和Tom下棋呢。
(3)can’t还可用来回答“ May I …? ”这样的问句。如:May I come in ? 我可以进来吗?No, you mustn’t. / can’t.不,你不能。
(4)can’t还可用于固定习语中。can’t help doing禁不住,情不自禁
can’t wait to do something迫不及待地要做…
如:She can’t help crying.她不禁大哭起来。
The children can’t wait to open the box.孩子们迫不及待地想打开盒子。
2. may的否定式为may not,译成“可能不”,如:He may not be at home.他也许不在家。
3.(1)mustn’t表示不许,不可。如:He mustn’t leave his room.他不许离开他的房间。
You mustn’t talk in class.你们不可以在课上说话。
(2) mustn’t也可用于以may表示要求时的否定回答中。如:—May I stand here? 我可以站在这里吗?—No, you mustn’t (can’t).不,不行。
4.(1)needn’t意为“不必”。如:You needn’t meet him unless you’d like to.你不需要见他,除非你愿意。
(2)needn’t + have+动词的过去分词,表没必要做而做了的动作,暗含时间或精力上的浪费。如: You needn’t have bought it.你没必要买它(但你却买了)。
5. shouldn’t表示不应该。如:You shouldn’t feel so unhappy over such little things.对于这种小事,你不应该感到这么不高兴。
二、含有情态动词的疑问句的回答:
1.对may引出的问句,可以有下列回答方式:Yes,you may. Yes, of course. Yes, certainly. Sure .
No, you mustn’t. No, you can’t.
2.对must引出的疑问句,回答方式为:Yes, …must. No,… needn’t/ don’t have to.
3.could在疑问句中,表示委婉的语气,此时could没有过去式的意思。
如:Could you do me a favour?你能帮我个忙吗?—Could I use your pen?我能用一下你的钢笔吗?—Yes, you can.可以。(注意回答)
4. 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.
5.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/ OK/ With pleasure. Certainly. (No, thank you .) Yes, please.
【例题】—Would you do me a favour and pass on my thanks to Lily?—________.
A.That’s right B.With pleasure C.It doesn’t matter D.No trouble
【解析】A.意为“对了”,B.意为“乐意效劳”, C.意为“没关系” D.意为“不费事”。答案:B
三、:情态动词表示推测的用法:
1、“情态动词+动词原形”表示对现在的推测。
1)、can表示推测时一般用于否定句或疑问句。如:That man can't be her husbandshe is still single.
Who is knocking at the door? Can it be the postman?
2)、must表示肯定的推测,一般用于肯定句中。如:He must be in his office now.Mr Li must be working now,for the lights in his office are still on.
3)、might表示推测时不一定是may的过去时,只是表示其可能性较小。如:The man may be the headmaster.
—Where is Mr Li?—He might be working in his office. —May Mr Li come?—He might not come here.
4)、Could表示推测时,语气can比要弱,说话者留有余地。如:—Could it be an animal?—It could not be,because it is not moving.
5)、Should表示推测的可能性比较大,仅比must的可能性小一点。如:It is already 10 o’clock now they should be there.
2、情态动词表示对过去可能发生的动作或存在过的动作的推测性用法。
1)、“must +have done/been------”表示“过去一定发生过某事或存在过某种状态”,不用于“musn’t+have-----”形式。如:She must have seen the film before,hasn’tshe?(注意反意疑问句的后半部分)
You must have met uncle Wang in the shop yesterday,didn’t you? (注意反意疑问句的后半部分)
2)、“should +have done /been-------”表示“本应当做某事,而实际上并没有做”;“shouldn’t+完成式”表示“本来不应当做,而实际上却做了”。以上结构常带有说话者的责备的感彩。如:You should have finished your homework earlier (but in fact you did not finish it on time).
You shouldn’t have gone to bed when you woke up at five (but in fact you went to bed again then).
3)、“needn’t+完成式”表示“本来没有必要做某事,而实际上却做了”。如:There was plenty of time. She needn't have hurried .
4)、“can’t /couldn’t+have done /been-------”表示“过去不可能发生了某事或存在过某种状态”。如:
I saw him just now. He can’t have gone to Japan.
She said the man couldn’t have stolen her car.
5)、“could+have done/been-------”表示“过去本来能够,可以做某事或成为某种状态,而实际上没有”,说话者有些遗憾。
“could sb. have done /been-------?”是它的问句形式。如:You could have stayed with the Smiths while you were in New York (but in fact you stayed in a nearby hotel .) Could Mr Li have helped this girl student?
6)、“may/might+完成式”表示“过去可能,本来可以于某事而实际上没有干”,might的可能性较小,语气较弱。如:He may have finished reading the book. She might have given you some help,however bus she was.
拓展:
情态动词后跟进行式,表示“想必正在……”,“可能正在……”,“应当正在”等意。 It’s twelve o’clock. They must having lunch.?? 现在是十二点。他们一定正在吃饭。 They may be discussing problem.?? 他们可能正在论讨这个问题。 He can’t be telling the truth.?? 他说的不可能是真话。 She shouldn’t be working like that. She’s still so weak.??她不应当那样干,她身体仍那么虚。
情态动词易混点归纳
易混点一: can和be able to:
两者表示能力时用法相同,但can只有原形“can”和过去式“could”两种形式,在其他时态中要用be able to来表示。另外be able to常常指经过努力,花费了时间和劳力之后才能做到某事。
易混点二:can和may
1. can和may均可用来征求意见或许可,意为“可以”,一般可互换使用。如:Can/ May I help you ? 我能帮助你吗?
2. can和may表示可能性时的区别:
1)在肯定句中用might,may,must,不用can
2)在疑问句中表示推测用can,不用might,may,must
3)在否定句中用can’t(不可能),不用may,must。如:She may be in the classroom .她可能在教室里。Where can they be now?他们现在可能在哪儿?That can’t be true.那不可能是真的。
易混点三: may be和maybe
用法区别 常用位置
may be may为情态动词,be为动词原形 句中,作谓语
maybe 副词,大概、也许,相当于perhaps 句首,作状语
例如:He may be wrong , but I’m not sure.也许他错了,但我也不确定。
易混点四:can’t和mustn’t
1. can’t根据其基本用法可译为:
(1)不会。如:I can’t speak English .我不会说英语。
(2)不能。如:We can’t do it now because it’s too dark.天太黑了,我们现在干不了。
(3)否定句中表示推测。“不可能”,如:The man can’t be our teacher because he is much younger than our teacher..那个人不可能是咱们老师,他年轻得多。
2. mustn’t意为“禁止、不许”,用来表达命令,表示强烈的语气。如:You mustn’t play football in the street. It’s too dangerous.你不可以在街上踢足球,太危险了。
易混点五:must和have to
1.must侧重于个人意志和主观上的必要。have to侧重于客观上的必要,可用于现在时、过去时和将来时。
2. have to可以用于多种时态;而must只用于一般现在或将来。如:The composition is due to hand in this morning, so I had to finish it last night.作文今天早晨到期,因此我不得不昨天晚上完成。
易混点六: used to do / be used to doing / be used to do…/ be used for doing sth
used to do表示过去常常发生的动作,强调过去,只用于过去,注意用to do,不用doing形式;
be used to doing意为“习惯做…”,be可有各种时态;
be used to do意为“……被使用去做……,”为被动语态形式。
be used for doing sth“用作……”如:My father used to eating meat.我父亲过去起床晚,但现在不得不早起了。She is used to eating meat.她习惯吃肉。He wasn’t used to eating in a restaurant.他不习惯在饭店吃饭。A knife can be used for cutting things.(刀可以用来割东西)/ A knife can be used to cut things.(刀可以用来割东西)
经典练习题:
1. I __________ you, because I I must be wrong.??A. dare not ask?? B. dare not? C. dare not asking?? D. dare to not ask2. There __________ some flowers in the garden.??A. were used to be?? B. used to be?? C. uses to be?? D. used to be having3. "__________ I take it out?"?? "I'm sorry, you __________."??A. Could ...couldn't?? B. Might...might not????C. Could...can?? D. May...can't4. You were stupid to climb tree. You __________ hurt yourself.??A. may? didn't you ???A. should post?? B. should have posted?? C. must have posted?? D. ought to post.6. All the lights are on, miths __________ up.??A. must get?? B. is getting?? C. must be getting?? D. would get7. He __________ lead a but he __________ not make it drink.??A. will...can?? B. may...can?? C. may...dares?? D. dare...can8. "Need we do this job now?"????"Yes, __________."??A. you need?? B. you should?? C. you must?? D. you can9. __________ to have lunch with us today???A. Do you likes?? B. Would you like?? C. Will you liked?? D. Have you liked10. He said that you __________ watch TV all the evening if you wished.??A. may?? B. must?? C. can?? D. might11. -Is John coming by train????? --He should, but he __________ not. He likes driving his car. ??A. must?? B. can?? C. need?? D. may12. Peter __________ come with us tonight, but he isn't very sure yet.??A. must?? B. can?? C. may?? D. will13. 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. could15. I wonder how he __________ that to the teacher.??A. dare to say?? B. dare saying??C. not dare say?? D. dared say16. Come on! We __________ hurry because there isn't much time left.??A. may?? B. must?? C. can?? D. need17. Amy did best in the English test. She __________ hard last week.??A. must have working?? B. should have worked?? C. should work?? D. must work18. The fire spread through the hotel very quickly but everyone??__________ get out.??A. had to?? B. would?? C. could?? D. was able to19. ---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 stayed20. It's nearly seven o'clock. Jack??__________ be here at any moment.??A. must?? B. need?? C. should?? D. can答案:1.A2.B3.D4.D5.B6.C7.B8.C9.B10.D11.D12.C13.B14.B15.D16.B17.A18.D19.A20.C