综观近年来的高考单项填空题,情态动词颇受高考命题人的青睐，成为考查的重点。本文拟结合高考试题,对高考情态动词题的考点做一剖析,以帮助同学们归纳出情态动词的主要用法。

一、表"能力"

can和be able to都表示能力，意思上没多大区别。但can只有现在和过去时，而be able to则有更多的形式，并且它还可以与情态动词连用。但当成功地完成某一具体动作时，通常不用could而用was/were able to来表示。这时was/were able to 相当于managed to，表示经过一番努力，终于能够完成某事。例如：

I'm able to (can) speak English and French.

It was so dark that we couldn't (weren't able to) see anything.

If you have a good sleep,you will be able to work out this problem.

You must be able to succeed.

He talked for a long time,and in the end he was bale to make her believe him.

高考示例

1.The fire spread through the hotel very quickly but everyone ____ get out.(NMET97)

  A.had to   B.would   C.could   D.was able to

2.A computer ____ think for itself,it must be told what to do.(MET91)

  A.can't   B.couldn't   C.may not   D.might not

二、表"推测"

1。从句式上

       肯定句疑问句否定句含义

must√一定，必然

can/could(could)√√疑问句：可能……？

否定句：不可能

may/might√√肯定句：也许

否定句：也许不

should/ought to √(按常理)理应；应该

注意：上表中can与could,may与might无时间区别，用过去式形式表示推测的语气较

弱。另外，could表推测时也可以用在肯定句中。

2．从时间上  

1）对现在或将来情况的推测时，用："情态动词+ do/be doing"结构。例如：

Don't eat it.It can/could be poisonous.

He must/may be at home now,for the light is on.

---I've bought thirty pints of beer. 

---That ought to be enough.

---Can it be your mother?

---No，it can't be her.It may be my father.

2）对过去情况的推测时，用："情态动词+ have done"结构。例如：

The road isn't wet ; it can't have rained last night .

---The lights have gone out. 

---He must have gone to sleep.

---Polly's very late. 

---She may have missed the train

高考示例

1.---Is John coming by train?

　---He should，but he _______ not.He likes driving his car.(NMET2000)

　A.must  B.can  C.need  D.may 

2.---Are you coming to Jeff's party?

　---I'm not sure.I _______ go to the concert instead.(NMET2000)

　A.must  B.would  C.should  D.might 

3.---When can I come for the photos?I need them tomorrow afternoon. 

　---They _______ be ready by 12：00 o'clock.(NMET98)

　A.can  B.should  C.might  D.need 

4.---There were already five people in the car but they managed to take me as well. 

　---It _______ a comfortable journey.(NMET95)

　A.can't be  B.shouldn't  C.mustn't have been  D.couldn't have been 

5.My sister met him at the Grand Theatre yesterday afternoon，so he _______ your lecture.(上海2000)

A.couldn't have attended 　B.needn't have attended 

　C.mustn't have attended 　D.shouldn't have attended 

6.Sorry I'm late. I ___________ have turned off the alarm clock and gone back to sleep again.(2000春季)

　A.might  B.should　C.can  D.will

7.Peter ___________ come with us tonight, but he isn't very sure yet.(NMET'93)

　A.must  B.may　C.can  D.will

8.I didn't hear the phone. I ___________ asleep.(NMET89)

　　A.must be  B.must have been  C.should be  D.should have been

9.Johnny, you ___________ play with the knife, you ___________ hurt yourself.(NMET96)

　　A.won't; can't  B.mustn't; may　C.shouldn't; must  D.can't; shouldn't

10.Put on more clothes. You ___________ be feeling cold with only a shirt on.(MET85)

　　A.can  B.could　C.would  D.must

11.It's nearly seven o'clock. Jack ___________ be here at any moment.(NMET'95)

　　A.must  B.need　C.should  D.can

12.Mary _______ be in Paris,for I saw her in town only a few minutes ago.(NMET94)

　　A.mustn't  B.can't  C.shouldn't  D.may not 

13.I didn't see her in the meeting room this morning. She _______ have spoken at the meeting.(MET 1991)

　　  A.mustn't  B.shouldn't　C.needn't  D.couldn't

14.Where is my pen?I ____ it？（MET88）

  A.might lose  B.would have lost  C.must have lost  D.should have lost

15.---I heard they went skiing in the mountains last winter.

  ---It ____ true because there was little snow there.(北京2000)

16.Jack ____ yet,otherwise he would have telephoned me.(上海97)

  A.mustn't have arrived  B.shouldn't have arrived  

C.can't have arrived  D.needn't have arrived

17.Mr Bush is on time for everything.How ____ it be that he was late for the opening ceremony?(上海2001春)

  A.can  B.should  C.may  D.must

18.Jenny ____ have kept her words.I wonder why she changed her mind.(MET91)

  A.must  B.should  C.need  D.would

19. He __________ have completed his work; otherwise, he wouldn't be enjoying himself by 

the seaside. (北京2005)

   A. shouldB. mustC. wouldn'tD. can't

20. --- I've taken someone else's green sweater by mistake.

       --- It ______ Harry's. He always wears green. (广东05)

  A. has to be   B. will be  C. mustn't be   D. could be

21.---Do you know where David is? I couldn't find him anywhere.

---Well . He       have gone far-his coat's still here.（湖北05）

A．shouldn'tB．mustn'tC．can'tD．wouldn't

22.-Tom is never late for work. Why is he absent today? (江西05)

  -Something ________ to him.

    A．must happen  B．should have happened

C．could have happenedD．must have happened

23. Helen ______ go on the trip with us, but she isn't quite sure yet.（安徽05）

A. shall  B. must  C. may  D. can

    24. This cake is very sweet. You ____ a lot of sugar in it. （辽宁05）

  A．should putB．could have putC．might putD．must have put

25. I was on the highway when this oar west past followed by a police car. They ____ at least 150 kilometers an hour. （重庆05）

A. should have been doing     B. must have been doing 

C. could have done       D. would have done

26.I thought you ____ like something to read,so I have bought you some books.(MET86)

  A.may  B.might  C.could  D.must

27. There _________ be any difficulty about passing the road test since you have practiced a lot in the driving school. （上海05）

A. mustn't  B. shan'tC. shouldn'tD. needn't

28. I _______have been more than six years old when the accident happened.（天津05）

 A. shouldn't    B. couldn't       C. mustn't   D. needn't

29. ---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.

---- Oh, dear! She _______ a lot of difficulties! (江苏05)

 A. may go through                       B. might go through

C. ought to have gone through             D. must have gone through

三、表"责备"、"批评"、"抱怨"

"有些情态动词+ have done"结构还可以表示"批评"、"责备"、"惋惜"语气。主要有：

1.needn't + have done"本来不必……"（但却做了某事）。例如：

You needn't have taken a taxi here,for it was very near to my house.

You needn't have walked so quickly since time was enough.

2.could（不用can）+ have done表示"本来能够……（而事实上未做到）"。如：

I could have come on time, but my car broke on the way.

You could have done better,but you were too careless.

3.might + have done "本来可以做到……（而事实上未做到）"如：

You might have worked out this problem,though it was a little difficult.

You might have been more carefull,otherwise you couldn't have made the mistake.

4.should／ought to＋have＋过去分词：肯定式表示"本应做某事(但没做)"；否定式表示

"本不该做某事(但做了)"

You ought not to have said such words to your parents.

According to the schedule, they should have arrived in Shanghai by now.

高考示例

1.I was really anxious about you. You _______ home without a word.(NMET 2001)

　　  A.mustn't leave  B.shouldn't have left　C.needn't leave  D.couldn't have left

　  2.I'm not feeling well in the stomach, I _______ so much fried chicken just now.( 上海2002)

　　  A.shouldn't eat　B.mustn't have eaten　C.mustn't eat　D.shouldn't have eaten

3.We _______ last night, but we went to the concert instead.(NMET 1992)

　　  A.must have studied　B.might study　C.should have studied　D.would study

　  4.I told Sally how to get here, but perhaps I _______ it out for her.(NMET 1994)

　　  A.had to write 　B.must have written　C.should have written 　D.ought to write

　  5.That young man has made so much noise that he _______ not have been allowed to attend the concert.(1992，上海)

　A.could  B.must  C.would  D.should

6．The plant is dead.I ____ it more water.(MET87)

  A.will give  B.would have given  C.must give  D.should have given

7.There was a lot of fun at yesterday's party.You ____ come,but why didn't you?(上海99)

  A.must have  B.should  C.need have  D.ought to have

8.There was plenty of time.She ____ .(MET87)

A.mustn't have hurried  B.couldn't have hurried

B.must not hurry  D.needn't have hurried

9.---I stayed at a hotel while in New York.

---Oh,did you?You ____ with Barbara.(NMET98)

  A.could have stayed  B.could stay 

  C.would stay  D.must have stayed

10.He ____ you more help,even though he was very busy.(MET90)

  A.might have given  B.might give

  C.may have given  D.may give

11. He paid for a seat, when he ______ have entered free.（山东05）

A. couldB. wouldC. mustD. need

三、表"必须"

1.must指主观上认为必须做某事，只有现在时态。其否定式mustn't表示"禁止"、"一定不要"。而have to指在客观条件下必须去做某事，多是被动的，在口语中常用have got to替代。其过去式为had to或had got to;可用于多种时态，否定式don't have to（=needn't）表示"不必"。构成疑问句时，要借助do。

You must pay the money,but you don't have to (=needn't) do so at once.

You mustn't play on the road again.

You will have to clean your own boots when you join the army.

He has no money with him;he has to borrow some from his friends.

2.回答 must 提问时，肯定用must;否定用needn't ;含有have to 问句的答语时，肯定用

have to或do;否定用don't have to或don't.如

    --- Must I start at once ?

--- No , you needn't(=don't have to).(不用mustn't)

---Does she have to go at nce?

---Yes,she does(=has to).

3.must在反意问句中

1）当must表示"应当、必须"时，附加疑问部分用mustn't.例如：

We must work hard this term,mustn't we?

2)当must表示推测时，附加疑问部分的助动词与must后的动词保持一致。例如：

He must be a teacher,isn't he?

You must know the reason,don't you?

They must have known of it,haven't they?

当must表示对过去情况推测，并且句中有明确的过去时间状语时，附加疑问部分用did,例如：

He must have finished the report last night,didn't he?

4. must表示与说话人的愿望相反，意思是"偏要"。例如：

Must you make so much noise？

Naturally，after I told her what to do， my daughter _____ go and do the opposite！ 

A.may B．can C．must D．should 

5. must表示主张、邀请，意思是"务必"、"一定要"。例如： 

You must come and see us． 

高考示例

1.-Who is the girl standing there?

   -Well,if you ____ know,her name is Mabel.(天津04)

  A.may  B.can  C.must D.shall

2.Children under 12 years of age in that country ____ be under adult supervision when in a public library.

  A.must  B.may  C.can  D.need

3. John, look at the time. ___________ you play the piano at such a late hour? （全国卷Ⅲ）

A．MustB．CanC．MayD．Need

    4. Tom , you         leave all your clothes on the floor like this ! （全国卷Ⅰ）

A．wouldn't B．mustn't C．needn't D．may not

    5.- Lucy doesn't mind lending you her dictionary. 

-- She ______ . I've already borrowed one. （湖南卷05）

      A. can't       B. mustn't   C. needn't    D. shouldn't