一、考點(diǎn)聚焦
1、 情態(tài)動(dòng)詞的基本用法
(1)can、be able to 和could
①can和be able to都表示能力，意思上沒(méi)多大區(qū)別。但can只有現(xiàn)在和過(guò)去時(shí)，而be able to則有更多的形式。但當(dāng)成功地完成某一具體動(dòng)作時(shí)，通常不用could而用was/were able to來(lái)表示。這時(shí)was/were able to 相當(dāng)于managed to，表示經(jīng)過(guò)一番努力，終于能夠完成某事。如：
Can you use chopsticks?
The wounded man still was able to get to the village and was saved in the
end.
②can和could
can和could都可以表示能力、技能、許可、建議或請(qǐng)求和可能性。但比較委婉客氣地提出問(wèn)題或陳述看法，一般用could，回答時(shí)則用can。如：
Could you help me carry the bag?
Can I help you?
(2)may/might
①may/might表示可能，但may比might可能性大。如：-Why isn’t he in class?
He may be sick.(生病的可能性較大)
-
He might be sick.(生病的可能性較小)
②may/might表示“允許”，may用于現(xiàn)在時(shí)或?qū)?lái)時(shí)，might常用在間接引語(yǔ)中表過(guò)去時(shí)，但might也可用于現(xiàn)在時(shí)間，表示比較委婉的語(yǔ)氣，回答用may。如：
He says we may leave.
He said we might leave.
③may / might 表示建議或請(qǐng)求，但might比may 更客氣，意思更肯定而無(wú)過(guò)去時(shí)態(tài)的含義。
Yes, you can / may.
-May / Might I use your bike? -
No, you mustn’t
（3）must
①must表示必須，應(yīng)該，沒(méi)有時(shí)態(tài)變化。如：
You must do everything as I do.
②must表示肯定的推測(cè)。如：
The light is still on, so he must be at home.
③mustn’t 表示禁止做某事。如：
You mustn’t smoke in the office.
（4）have to
have to 表示“必須、不得不”，是由于某種外界（客觀）原因而“必須”，“不得不”做某事，也可表示經(jīng)常的或習(xí)慣性的事“必須”做。have to的否定形式表示不必。have to可用于多種時(shí)態(tài)中。如：
You will have to clean your own boots when you join the army.
I have to be at my office every evening.
（5）should / ought to
①should和ought to表示應(yīng)當(dāng)、應(yīng)該，前者比后者語(yǔ)氣輕。如：
You should / ought to work hard.
②should / ought to work hard.
Since she is not here, whe should / ought to be in the classroom.
③should / ought to的否定形式表示禁止之意。如：
Children shouldn’t smoke.
④should可表示陳述意見，推出建議或請(qǐng)求；而ought to可以表示勸告之意。如：
You ought to respect your parents.
He suggested that they should leave at once.
（6）will / would
①will 用于各種人稱表示“意志”、“意愿”或“決心”等，否定式won’t + 動(dòng)詞。如：
I will tell you all about it.
Tom won’t do such a thing.
②will用于疑問(wèn)句中，常用在第二稱時(shí)表示說(shuō)話人向?qū)Ψ教岢觥罢?qǐng)求”或“詢問(wèn)”如：
Will you please tell her the news when you see her?
③will 表示習(xí)慣性的動(dòng)作，有“總是”、“慣于”的含義。如：
Fish will die out of water.
④would 表示客氣的請(qǐng)求、建議或意愿。如：
Would you please be quiet?
Would you like coffee?
⑤would 表示過(guò)去反復(fù)發(fā)生的動(dòng)作。如：
When I passed my school I would see my teachers who taught me 5 years ago.
（7）need
need 作“必要”講，既可作情態(tài)動(dòng)詞，也可作實(shí)義動(dòng)詞。作實(shí)義動(dòng)詞時(shí)后面的動(dòng)詞不定式要帶to，其變化與一般動(dòng)詞相同。如：
I need to think it over.
-Need you go now? -Yes, I must./No, I needn’t
（8）dare
dare表示“敢”的意思。作為情態(tài)動(dòng)詞時(shí)，主要用在疑問(wèn)句和否定句中。dare若作實(shí)義動(dòng)詞，后面可帶to的不定式，此時(shí)to也可以省略。dare與need的用法相似。如：
How dare you say that?
She doesn’t date(to)ask her father.
（9）used to
used to表示過(guò)去常常發(fā)生的動(dòng)作或存在的習(xí)慣，但現(xiàn)在已不復(fù)存在了。如：
He used to smoke.
（10）shall
①shall作為情態(tài)動(dòng)詞用于第二、三人稱，表示說(shuō)話人的意愿，有“命令”、“警告、威脅、強(qiáng)制”和“允許”等意思。如：
We shall do as our teacher says.
You shall have the book as soon as I finish it.
②在疑問(wèn)句中，shall用于征求對(duì)方的意見或請(qǐng)求指示，常用于第一、第三人稱。如：
Where shall he wait for us?
Shall we go out for a walk?
2、情態(tài)動(dòng)詞表示推測(cè)或判斷的用法
下表即是表示推測(cè)的情態(tài)動(dòng)詞使用的場(chǎng)合：
情態(tài)動(dòng)詞 對(duì)現(xiàn)在和未來(lái)的推測(cè) 對(duì)過(guò)去的推測(cè) 使 用 場(chǎng) 合
must must + 動(dòng)詞原形 must have done 肯定句
may / might may / might + 動(dòng)詞原形 May / might have done 肯定句、否定句
can /could can / could do Can / could have done 否定句、疑問(wèn)名（could可用于肯定句）
should 用來(lái)表示一種估計(jì)的情況“按理會(huì)/估計(jì)會(huì)”should do/be should have done 肯定句、否定句、疑問(wèn)句
例如：
It must have rained last night.
She may not be at home. = It is possible that she is not at home.
She can’t be at home. = It is impossible that she is at home.
They should be there right now.
3、情態(tài)動(dòng)詞在虛擬語(yǔ)氣中的用法
情態(tài)動(dòng)詞用于虛擬語(yǔ)氣中表示責(zé)備的感情色彩，用法如下：
（1）should have done表示“本來(lái)應(yīng)該做某事而實(shí)際上未做”，而shouldn’t have done則表示“本不應(yīng)該做某事而實(shí)際上做了”。如：
You should have told me about it earlier.
You shouldn’t have said such words to your parents.
（2）ought to have done也表示“本應(yīng)該……”而ought not to have done則意為“本不應(yīng)該……”。如：
You ought to have told me about it earlier.
You ought not to have said such words to your parents.
（3）needn’t have done表示“本無(wú)必要做某事而實(shí)際上做了”。如：
You needn’t have walked so quickly since time was enough.
（4）could have done表示“本來(lái)有可能……而事實(shí)上未做到”。如：
I could have come on time, but my car broke on the way.
二、精典名題導(dǎo)解
選擇填空
1. I was really anxious about you. You________home without a word.(NMET 2001)
A.mustn’t have B.shouldn’t have left
C.couldn’t have left D.needn’t have
解析：答案為B。本題考查的是情態(tài)動(dòng)詞在虛擬語(yǔ)氣中的用法。題目給出的條件是“我確實(shí)非常擔(dān)心你”，因此后面可知應(yīng)是責(zé)備you不應(yīng)該沒(méi)說(shuō)一句話就離開了。
2.-Are you coming to Jeff’s party?
-I’m not sure. I__________ go to the concert instead.(NMET 2000)
A.must B.would C.should D.might
解析：答案為D。本題考查情態(tài)動(dòng)詞的基本用法。由題目中“I’m not sure”,表明我可能去Jeff’s party，也可能去音樂(lè)會(huì)，故用might。
3. -Will you stay for lunch?
-Sorry, ____________. My brother is coming to see me.(NMET 99)
A.I mustn’t B.I can’t C.I needn’t D.I won’t
解析：答案為B。本題考查表示請(qǐng)求的英語(yǔ)口語(yǔ)，用will來(lái)向第二人稱提問(wèn)的疑問(wèn)結(jié)構(gòu)，是表示一種請(qǐng)求和意愿，是用疑問(wèn)的形式來(lái)表達(dá)較為婉轉(zhuǎn)的祈使語(yǔ)氣，意思是“請(qǐng)你……，好嗎”，對(duì)于這種問(wèn)句的肯定回答是：Suree! Gertainly! Yes, of course. I’d be glad to 等；否定回答通常是：I’m sorry, I can’t. No, I’m afraid I can’t. I’m sorry, but … I’d like to, but …等。注意情態(tài)動(dòng)詞表客氣的用法及其在一般疑問(wèn)句中的問(wèn)與答。
情態(tài)動(dòng)詞
1．I thought you 1ike somethjng to read，so I have brought you some books．
A．may B．might C．could D．must
2．There was plenty of time．She ．
A．mustn’t have hurried B．couldn’t have hurried
C．must not hurry D．needn’t have hurried
3．The plant is dead．I it more water．
A．Will give B．would have given C．must give D．should have given
4．You return the book now．You can keep it till next week if you like．
A．can’t B．mustn’t C．needn’t D．may not
5．Tom ought not to me your secret，but he meant no harm．
A．have told B．tell C．be telling D．having told
6．He you more help，even though he was very busy．
A．might have given B．might give C．may have given D．may give
7．He at the meeting this morning．He was in hospital at the time．
A．couldn’t have spoken B．mustn’t have spoken
C．shouldn’t have spoken D．needn’t have spoken
8．He must be in the classroom， he?
A．mustn’t B．can’t C．isn’t D．can
9．-You were driving at 100 km an hour，sir．
-But officer，I ．My car can’t go more than 80．
A．may not have been B．couldn’t have been
C．wouldn’t have been D．needn’t have been
10．-Did you visit the famous museum?
-No．We it，but we spent too much time shopping．
A．could have visited B．must have viste
C．can’t have visited D．shouldn’t have visited
11．-When can I come for the photos? I need them tomorrow afternoon．
-They be ready by 12：00．
A．can B．should C．might D．need
12．You to the meeting this afternoon if you have something important to do．
A．needn’t to come B．don’t need come
C．don’t need coming D．needn’t come
13．Put on more clothes．You be feeling cold with only a shirt on．
A．can B．could C．would D．must
14．-There were already five people in the car but they managed to take me as well．
-It a comfortable journey．
A．can’t be B．shouldn’t be C．mustn’t have been D．couldn’t have been
15．I think all drivers seat belts．
A．should wear B．had better wear C．can wear D．have to wear
16．-Don’t forget to come to my birthday party tomorrow．
- .
A．I don’t B．1 won’t C．I can’t D．I haven’t
17．I to1d Sally how to get here，but perhaps I it out for her．
A．had to write B．must have written C．should have written D．ought to write
18．Peter come with us tonight，but he isn’t very sure yet.
A．must B．may C．can D．will
19．A computer think for itself；it must be told what to do．
A．can’t B．couldn’t C．need D．would
20．Jenny have kept her word．I wonder why she changed her mind．
A．must B．should C．need D．would
21．--Could I borrow your dictionary? Yes，of course you ．
A．might B．will C．can D．should
22．-I heard they went skiing in the mountains last winter．
-It true because there was 1ittle snow there．
A．may not be B．won’t be C．couldn’t be D．mustn’t be
情態(tài)動(dòng)詞
1-5 BDDCA 6-10 AACBA 11-15 BDDDA 16-20 BCBAB 21-22 CC