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发布者:zhanglaoshi        发布时间:2019-08-21 11:27:10



情态动词是一类比较特殊的词汇,它本身没有固定的词义,需要和另外一个动词一起才能构成谓语,用来表示说话者的态度、 语气等。除ought需要跟动词不定式外,其余情态动词后跟动词原形。情态动词没有人称和数的变化。

可能性顺序:must> will ≥ would > ought to ≥ should> can > could > may ≥ might

can的用法 1.表示能力(能做某事)

Can you ride a bicycle?

I can't promise anything, but I will do what I can.

be able to 可以表示相同意思,并还可以明确表示未来时间,甚至用于完成时 Our baby will be able to walk in a few weeks.

Since his accident he has not been able to walk properly.情态动词


I can call you tomorrow.

I'm afraid I can't go with you.


Scotland can be very cold.

It can be quite windy on the hill.


That can't be Mary- she's in hospital.

Can he still be alive after all these years.

后面有时跟完成时和进行时 She can't be telling the truth.她讲的不可能是真话 He can't have taken it upstairs.他不可能把它拿上楼了情态动词


You can park here.

You can't smoke here.

could的用法 1.作为can的过去式,表示过去的情况

a.表示能力 I could see her through the window.

也可用was/were able to He said he had lost his passport and hadn't been able to leave the country.


I thought I could smell something burning.单击此处添加标题



Could you send me an application form?申请表 You could have a nursery here.

b.用于疑问及否定句,表示惊异,不相信 Could this be true:


3.用于虚拟条件句 You could get into university if you applied.

If you tried you could do that work.



Don't worry-they could have just forgotten to phone.

She could not have been more than 6 then.他那时不可能超过6岁。

b.表示“本来可以”、“差点就” He could have sent a message.

本可以 I could have died laughing.

我差点笑死啦 c.提出委婉的批评 You could have been more considerate.本可以考虑更周到 You could have told me beforehand.


may的用法 1.用来提出问题,询问可不可以:

May I use your phone?

I may leave now, may not I?我现在可以走了,对吧?

2.用于陈述句,表示“可以” You may come if you wish.

如果你愿意,你可以来 You may not take photographs in the museum.

3.表示“可能” He may have gone abroad.

They may be waiting at the station.情态动词

4.表示祝愿 May you happy!

May God be with you.

Long may she live to enjoy he good fortune! 祝她长寿好运。



may as well 不妨 You may as well bring me a chocolate.

你不妨给我带一块巧克力 b.may...but 或许……但是 They may be good reports, but they seem to lack facts.

报告或许不错,但似乎缺乏事实 c.may well...


His appearance has changed so much that you may well not recognize him.情态动词

might的用法 1.作为may的过去式

a.表示“可以” He asked if he might use the phone.

是否可以用电话 I thought you might stay with us.

我想你可以住我们这 b.表示“可能”(或许会)

He said he might be late.

I guessed he might come tomorrow.



Might I have a little brandy:

白兰地 You might just call at(访问) the chemist(药店) on the way home.情态动词

b.表示“可能、或许” He might tell his wife.

She might still be waiting there.

3.用于虚拟语气条件句 The pills might have helped him, if he had taken them regularly.

If you invited him, he might come.

If you didn't mind, we might go there.

4.表示轻微的埋怨或批评 Honestly, you might have told me! 说真的,你本可以告诉我 They might at least have phoned if they are not coming.


5.用于might as well,表示“不妨……” We might as well go together.

Shall we walk?-We might as well.

must用法 1.表示“必须、一定、得……”(多指现在或将来情况)

The work must be finished by the end of the week.

I am afraid I must be going.

否定形式表示“不得、一定不要” You mustn't take photographs in here.

Cars must not park in front of the door.

注:表示过去的情况可以换为had to,虽然must也可表示过去情况情态动词

2.表示推想,“一定、准是” You must be hungry.

I must have left my cheque book as home.


We must think of this matter very seriously.

ought 用法 ought总是和to连用,表示:


I ought to write to him today.

Ought I to write to say thank you?情态动词

注:后面的不定式可接完成时、进行时或被动 2.表示揣测 She ought to pass the exam.

应当能过 The water ought to have boiled by now.

shall, will, should, would兼有助动词和情态动词作用 will的用法 1.用于将来时 2.用于疑问句表示请求:

Bring me the newspaper, will you?

Won't you take off your coat?情态动词


a.愿意,肯 I will have nothing to do with this matter.

我不愿和这事扯上关系 b.决心,承诺 I won't let her down in any way.

不会做对不起她的事 c.习惯,倾向 These things will happen.

这样的事总要发生 d.命令,叮嘱 You will stay here till you are relieved.

放你走你才能走 e.表示猜测 That will be the postman at the door.门口想必是邮差情态动词

would的用法 1.作助动词的用法

a.用来构成过去将来时态 b.用来婉转的提出请求、问题、看法:

Would you help us?

Let's fix a day.

Would Saturday night suit you?

2.用于虚拟语气 3.用于过去情况,表示“愿意、肯、会”(will的过去式)


5.表示猜测 I would say she is about 40.我猜她40岁。情态动词

6.一些固定结构 would like=would love 想 would hate to do 不愿意 would prefer to do 愿意 would rather do 愿 would sooner do 宁愿 shall的用法 1.作助动词用法:主要用于第一人称,构成疑问句征求对方意见:、 Shall I turn on the light:

要不要我把灯打开 What shall we do this evening?

2.shall 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 You shall fail if you don’t work hard.(警告)

He shall have the book when I finish it.(允诺)

He shall be punished.(威胁)情态动词

should的用法 1.情态动词--表示“应该”(接近ought to),后可接完成时 You should try that new restaurant.

You should not have trusted him so readily.

你不应轻易相信他 2.委婉语气 I should be grateful for your help.

I should like to phone my lawyer.

3.“竟然” I find it quite astonishing that he should be so rude to you..

我惊讶他竟然对你如此无礼 4.虚拟语气 5.表示猜测情态动词

need的用法 1.情态动词用法


You needn't make 2 copies.

b.用在带有否定意思的句中 Nobody need be afraid of catching the disease.

I don't think you need take it too seriously.

c.构成疑问句 Need I tell Tom?

Why nee you go today:



a.名词或代词 All living things need water b.不定式 I need to get some sleep.

c.动名词 His hair needed cutting.

d.复核宾语 I need my coat mended.情态动词

dare的用法 1.做情态动词用法:dare表示“敢”,这时没有人称形式变化,但是有过去式dared。主要用于:


I daren't ask her to marry me.

我不敢求她嫁给我 He doesn't dare (t0) say anything.

她什么都不敢说 They didn't dare (to) disobey.

他们不敢不服从也可用在带有否定意思的句子中:no, hardly, never, seldom...

No one dared speak of it.

没人敢提及此事 b.疑问句或条件句 Dare you interrupt him:

你敢打断他么 Jump if you dare.

How dare you speak to me like that! 你怎么敢对我这样讲话 If you dare speak to me like that again, you will be sorry.


c.用于I dare say..., don't you dare(你敢!)引导的句子中 I dare say you are right.

我认为你是对的 Don't you touch that vase.

不准碰那花瓶 2.作及物动词:

a.敢做某事 He dared to walk the tightrope without a net.

他敢不用安全网踩钢丝 b.敢于面对、尝试 He will dare any danger.


be able to 的用法 1.表示能力时,可以和can互换,而be able to 可以用于更多时态,接情态动词或做非谓语。情态动词

have to 的用法 1.have to的意思接近must, must强调个人意愿,have to表示客观上的必要性,译为“不得不”,否定译为“不必” 2.have got to do意思与have to差不多

had better 用法 1.用法接近情态动词,跟动词原形,表示“最好……” We'd better go before it gets dark.

had better be dong 表示立即做某事 We'd better be getting out clothes ready.

我们最好马上把衣服准备好 2.had best ≈ had better We had best have his opinion first.



a.纯条件的虚拟语气 b.与现在事实相反地虚拟语气 c.与过去事实相反地虚拟语气 d.与将来事实相反地虚拟语气

1.纯条件虚拟语气基本句型:if从句动词用现在时,主句为现在时助动词跟动词原形 If + 主句 + 一般现在时动词,主语 + will/can/may/should/shall/must/ought to + 动词原形表示:若if的条件存在,就会有预期的结果。纯条件句的副词连接词不只if,还有once一旦,when当, before,as soon as, unless,用法相同虚拟语气

Once I have money , I will buy a car.一旦我有钱,我会买辆车。


When he finish it , he may come.他做完事,就可以来了。

As soon as he arrives , I will let you know .他一到,我就会让你知道。

I won't do it unless you help me.除非你帮助我,否则我不会去做这件事

I will not do anything before he arrives·.


2..与现在事实相反地虚拟语气基本句型:if从句的动词用过去时,主句则用过去时助动词 If + 主语+一般过去时动词,主语+would/could/might/should/ought to +原形动词.


If I were rich , I would help you ·如果我有钱,我就会帮助你 If you were in my shoes , what would you do :


If 1 could fly , I would fly to you · 如果我能飞,我会飞向你。虚拟语气

3..与过去事实相反地虚拟语气基本句型:if从句的动词要用过去完成时,主句则是助动词的过去时再加上“have+过去分词” If +主语 + had + done,主语+would/could/might/should/ought to + have + done 表示与过去事实相反的情况,一见到此类过去完成时的句型出现时,我们就确知当时的事实并非如此。

If 1 had arrived earlier , 1 could have met him .要是当时我早点到J就可以见到他了 If he had taken your advice, he would have avoided making the mistake·.

要是他当时听了你的劝告,就会避免犯了这个错注:区分if + 主语+had+名词和 if + 主语+had+过去分词。前者为与现在事实相反的虚拟语气,译为 “有”,主句中置一般过去时的助动词即可;后者为与过去事实相反的虚拟语气,译为“曾经、已经”,主句使用“过去时助动词+have+过去分词”。虚拟语气


if从句一定要加助动词should , " if.二should ”译成“万一”。若假设的可能性很低,则主句要置过去时助动词(和与现在事实相反的虚拟语气相同),但若假设的可能性很高,则主句要用现在时助动词(与纯条件虚拟语气相同)。


If+主语+should+原形动词,主语+would/could/might/should/ought to+原形V

If you should fall ill , the meeting would be put off .万一你生病,会议将延期。---你不太可能生病,会议不太可能延期


If+主语+should+原形V , 主语 + will/can/may/should/ought to + 原形v

If you should fall ill , the meeting will be put off.



If I should be late , be sure to wait for me.



5.其他注意事项 (1)虚拟语气的省略:

虚拟条件句中的连词if 省去,而将had, should, were 等词提到主语之前 If she had been here five minutes earlier she would have seen her old friend.

→ Had she been here five minutes earlier she would have seen her old friend.

If she were here, she would attend the meeting too.

→Were she here, she would attend the meeting too.


if = in case (that),on condition that, provided / providing ( that ) , so long as(只要),as long as(只要),此类连接词通常只用在表纯条件的虚拟语气中。

(3)but for...

若非/要不是⋯ 此类句型仅限于与现在事实及过去事实相反的虚拟语气。虚拟语气


But for+名词, 主语+could/would/might/should/ought to + 原形V b.与过去事实相反:若非当时...就...

But for+名词, 主语+could/would/might/should/ought to + have + done 注:But for 一可用介词without代替 (4)lest...


以免⋯ ⋯ lest 为副词连接词,引导状语从句。在该从句中,助动词一律用should。而should往往予以省略,故该从句中的动词必定是原形动词。

lest...should...=for fear that + 主语 + may+原形V(表现在或将来的状况)/might+原形V(表过去的状况)=for fear of十动名词 You must study hard lest you should fail the exam.= You must study hard for fear that you may fail the exam.

= You must study hard for fear of failing the exam.你必须用功念书,以免考试不及格。虚拟语气

(5)as if...=as though...


a.表示极大的可能,动词使用一般时态 It looks as it (as though) it is going to rain· 看起来好像要下雨了 b.表与现在事实相反,动词使用一般过去时(did, were)

Mr.Wang loves me as if(as though)I were his own child.

王先生爱我就像我是他的孩子一样 c.表与过去事实相反,动词使用过去完成时(had done)

He looked as if(as though) nothing had happened.

他看起来就像什么事都没发生过一样 d.


(6)What if ...should ...:




What if he should come:

要是他来了怎么办 What if it should rain:


(7)It is time + that从句的一般过去时:

It is time/about time/high time + that 从句一般过去时该是……的时候了 It is time (that) he went to bed.


It is high time our children learned some manners.

(8)if only...


If only he were here.

要是他现在在这里就好了 If only I had known it earlier.





I wish I were a teacher.

He wished he hadn't said that.

I wish it would rain tomorrow.

b.I wish (that)⋯真希望⋯ ⋯就好了 I wish I had studied harder when young.

真希望我当时能更用功就好了 (10)hope hope之后接that从句时,使用一般时态,表示极大的可能性。即表示现在的状况时用现在时,表示将来的状况时用将来时,表示完成的状况时用完成时J表示进行的状况时用进行时。


I hope (that) he is safe.

我希望他安然无恙 b.表示将来的状况:

I hope he will be back.

我希望他会回来 c.表示进行的状况:

I hope they are having a good time.我希望他们正玩得很愉快 d.表示完成的状况:

I hope they have finished the work·.

我希望他们已经把工作做好了 (11)对过去事物的猜测的三种句型


must have + 过去分词一定曾经⋯ ⋯ He is learned:

he must have received a good education.他博学多闻,一定受过良好的教育虚拟语气


may have +过去分词可能曾经· · ⋯

He looks tired:

he may have stayed late last night.


c .

cannot have+过去分词不可能曾经

He is honest :

he cannot have stolen Mary's money.


(12)" didn't need to+v原形 ”与“ need not have + 过去分词”的区别:

" didn't need to+v原形” 表示过去的事实,即“不必⋯ ⋯同时亦没有如此做” ;而“need not have + 过去分词” 表示与过去事实相反的虚拟语气,即“不必⋯ ⋯但却这么做了”

As 1 had enough money , I didn't need to borrow any from him .



Since you had enough money , you needn't have borrowed money from me, but why did you still borrow some :


(13)意志动词:“建议” 、 “要求” 、 “命令” 、 “规定” 、 “主张”等五大类。之后用that从句作宾语时, 由以从句中要使用助动词should,而should往往予以省略。

a.建议:suggest 、 recommend 、 advise 、 urge(呼吁)、 propose 、 move(提议) b.要求:ask 、 desire 、 demand 、 require 、 request 、 insist(坚持要求) c.命令:order 、 command d.规定:rule 、 regulate 、 stipulate e.主张:advocate 、 maintain 圆:They suggested that he(should)come home on time.

他们建议他准时回家 Mary desired that Peter(should)treat her nicely.

玛丽请求彼得好好待她 The mayor ordered that the police officer(should)be investigated· 市长下令要调查那名警官 The principal ruled that no student (should) play truant .


(14)suggest 、 insist 、 maintain的另类用法:suggest若表示“暗示” 、 insist若表“坚信” 、 maintain若表示“坚决认为”时,则之后的that从句用一般时态。

His words suggested that he wasn't telling a lie.

他的话中暗示他绝不是在说谎 He insists that the job isn't so difficult as one may think.

他深信这份工作没有一般人想象的那么困难 John maintained that he had met the girl before.

约翰确信他曾经见过那女孩 (15)表示“有必要的”形容词,修饰that从句时,该从句亦须使用助动词should,而should往往予以省略。

此类形容词通常有8个:necessary(有必要的)、 important(很重要的)、 essential(不可或缺的)、imperative(有绝对必要的)、 urgent(紧急的)、 desirable(合意的)、 recommendable(值得推荐的)、 advisable(明智的)

It is necessary that he (should) work hard .


(16)that从句若是置于意志动词变成的名词之后,而与该名词形成同位语时,that从句中也要使用助动词 should,而should往往予以省略。

It is my suggestion that he(should)study abroad· 我建议他出国念书