情態(tài)動(dòng)詞是中學(xué)英語(yǔ)語(yǔ)法的重要項(xiàng)目之一,也是歷年高考的熱點(diǎn)。盡管情態(tài)動(dòng)詞的用法很復(fù)雜,很難掌握,但從歷屆高考題看,情態(tài)動(dòng)詞的命題熱點(diǎn)主要集中在以下幾個(gè)方面:
一、情態(tài)動(dòng)詞的非推測(cè)性用法
1.情態(tài)動(dòng)詞表示能力時(shí),一般用can /could或be able to 。be able to用于表示能力并且可用于各種時(shí)態(tài),而can只有一般現(xiàn)在時(shí)和一般過(guò)去時(shí)兩種時(shí)態(tài)。此外,當(dāng)表示過(guò)去成功地做成了某事時(shí),只能用was / were able to。
The fire spread through the hotel very quickly but everyone ________ get out .
(97’NMET)
A. had toB. would
C. could D. was able to
【解析】本題表示過(guò)去“成功地從火里逃出來(lái)”,故答案選【D】。
2. can / could和may / might
may表示允許,否定形式為mustn’t(不允許);can/could, may/might都可用來(lái)表示請(qǐng)求允許或許可。過(guò)去式could和might常用于疑問(wèn)句,表示禮貌,答語(yǔ)中常用原形can或者may,不可再用過(guò)去式could或might。
(1) — Could I borrow your dictionary?
— Yes, of course you________ .(92’NMET)
A. mightB. will C. canD. should
【解析】本題的前一句用could提問(wèn),表示委婉的請(qǐng)求,答語(yǔ)中應(yīng)用原形can,故答案選【C】。
(2) — I hear you’ve got a set of valuable Australian coins. _______ I have a look?
—Yes,certainly.(02’北京春招)
A. DoB. MayC. ShallD. Should
【解析】 “may / might I … ”表示請(qǐng)求對(duì)方允許或許可;“Shall+ I / we …”表示征求對(duì)方意見(jiàn),故答案選【B】 。
3. must與have to都可以表示“必須”的意思,但must表示主觀看法,have to則側(cè)重于客觀需要。
(1) — What do you think we can do for our aged parents?
— You ________ do anything except to be with them and be yourself.(07’湖南卷)
A. don’t have to B. oughtn’t to
C. mustn’t D. can’tKey:【A】
(2) All passengers must wear seat belts.
【固定短語(yǔ)】 If you must表示無(wú)可奈何地同意某人干某事。
— May I smoke here ? (06’山東卷)
— If you ________ , choose a seat in the smoking section.
A. shouldB. could
C. may D. mustKey:【D】
4. will作情態(tài)動(dòng)詞時(shí)有以下用法:
(1)當(dāng)情態(tài)動(dòng)詞will表示意愿或決心時(shí),也可用于條件狀語(yǔ)從句。
If you will listen to me, I’ll give you some advice on how to learn English.
(2) 表示請(qǐng)求。
Will you give me a hand ?
(3) 表示沒(méi)有時(shí)間限制的傾向性動(dòng)作或習(xí)慣。
Oil will float on water.
5.would的用法
(1)表示禮貌的請(qǐng)求。
Would you close the window, please?
(2)表示過(guò)去的傾向性動(dòng)作或習(xí)慣。
John promised his doctor he ________ not smoke, and he has smoked ever since. (08’北京卷)
A. might B. should
C. could D. would Key: 【D】 (3) 表示想必現(xiàn)在 / 過(guò)去……;現(xiàn)在/過(guò)去可能……
He would be back today / yesterday .
6. shall的用法。
shall用于第一、三人稱(chēng)疑問(wèn)句,用來(lái)征求對(duì)方意見(jiàn);用于第二、三人稱(chēng)陳述句,表示說(shuō)話(huà)人的命令、警告、允諾、威脅或決心等。
(1) — What’s the name?
— Khulaifi . ________ I spell that for you?(06’北京)
A. Shall B. Would
C. Can D. MightKey:【A】
(2) — What does the sign over there read? (07’四川)
—“No person ________ smoke or carry a lighted cigarette,cigar orpipe in this area.”
A. will B. may
C. shall D. must Key: 【C】
7. should 的用法
(1) Should 表示勸告、建議、命令,有義務(wù)、有責(zé)任做某事,意為“應(yīng)該”。
— I think I’ll give Bob a ring.
— You ________. You haven’t been in touch with him for ages. (06’江蘇)
A. will B. may
C. have to D. shouldKey: 【D】
(2) Should 可以用來(lái)表示“推測(cè)”,意為“可能、該”。相當(dāng)于be expected to。往往指具有一定的客觀根據(jù)或根據(jù)合理的推斷,且所期待的事幾乎已成為事實(shí),因此不是虛擬語(yǔ)氣。
— How’s your tour around the North Lake? Is it beautiful?
—It ________ be, but it is now heavily polluted.(07’全國(guó)I)
A. willB. would
C. should D. mustKey: 【C】
(3) should可以用于較強(qiáng)語(yǔ)氣的假設(shè)情形中,表示“竟然;萬(wàn)一”之意。
________ fired, your health care and other benefits will not be immediately cut off.(06’湖北)
A. Would you beB. Should you be
C. Could you be D. Might you be
Key:【B】
8. need用作情態(tài)動(dòng)詞,僅用于否定句和疑問(wèn)句或條件句。在肯定句中要用must, have to, should, ought to或?qū)eed當(dāng)作行為動(dòng)詞使用。
We need to work hard.
You needn’t worry = You don’t need to worry.
If you need go there, please let me know.
【注意】 (1) needn’t = don’t have to 不必 。
— What sort of house do you want to have? Something big? (08’陜西)
— Well, it ________ be big — that’s not important.
A. mustn’t B. needn’t
C. can’t D. won’t Key:【B】
(2) need還可作實(shí)義動(dòng)詞
(a) The elderly man needs / wants /requires looking after every day . = The elderly man needs / wants / requires to be looked after every day .
(b) Does he need to take the medicine four times a day ?
9. dare的用法
(1) dare作為情態(tài)動(dòng)詞,主要用于疑問(wèn)句,否定句和條件從句中,一般不用于肯定句.
a. How dare you say I’m unfair ?
b. He daren’t speak English before such a crowd, dare she ?
c. If he dare break the rule, he will be punished.
(2) dare作實(shí)義動(dòng)詞,有時(shí)態(tài)、人稱(chēng)和數(shù)的變化。所不同的是,在肯定句中,dare 后面通常接帶to的不定式;在否定和疑問(wèn)句中, dare后可接帶to或不帶to的不定式。
(a) I dare to swim across the river.
(b) He doesn’t dare (to) answer.
二、情態(tài)動(dòng)詞的推測(cè)性用法
can, could, may, might, must,其中,must所表示的可能性最大,最有把握,意為“一定”,而其否定式mustn’t表示“禁止、不準(zhǔn)”;表示“不可能”要用can’t或couldn’t;may 和 might表示可能性時(shí),主要用于肯定句中,might相對(duì)于may 來(lái)說(shuō),表示的可能性更小些。can和could主要用于否定句和疑問(wèn)句中。情態(tài)動(dòng)詞表示猜測(cè),我們首先要清楚被猜測(cè)的時(shí)間,其次要看有無(wú)事實(shí)根據(jù)。若有事實(shí)根據(jù),則無(wú)論是肯定還是否定的猜測(cè),猜測(cè)語(yǔ)氣最強(qiáng)且符合時(shí)間要求的為最佳答案;若無(wú)事實(shí)根據(jù),純憑主觀臆斷,則猜測(cè)語(yǔ)氣最弱且符合時(shí)間要求的為最佳答案。
1. can表示可能性時(shí),指的是理論上的可能,它通常不用來(lái)表示某事實(shí)際發(fā)生的可能性或真實(shí)性。
You ________ be hungry already — you had lunch only two hours ago!(08’浙江)
A. wouldn’t B. can’t
C. mustn’tD. needn’tKey:【B】
如果我們要表達(dá)某事發(fā)生的實(shí)際可能性,要用may, could或might等。
(1) Children under 12 years of age in that country ________ be under adult supervision when in a public library. (04’上海)
A. must B. may C. can D. need
Key:【B】
(2) — I’ve taken someone else’s greensweater by mistake.
— It ________ Harry’s. He always wears green.(05’廣東)
A. has to beB. will be
C. mustn’t beD. could be
Key:【D】
can表示猜測(cè),用于肯定句,表示“一時(shí)的特征”可譯為“有時(shí)會(huì)”。
Peter ________ be really difficult at times even though he’s a nice person in general.(08’遼寧)
A. shall B. should
C. can D. must Key:【C】
2. may和might表示推測(cè)只能用于肯定句或否定句,不能用于疑問(wèn)句中。
Although this ________ sound like a simple task, great care is needed. (08’四川)
A. must B. mayC. shall D. should
【解析】題中沒(méi)有客觀事實(shí)根據(jù),猜測(cè)語(yǔ)氣要求最弱,故答案選【B】。
Helen ________ go on the trip with us, but she isn’t quite sure yet. (05’安徽)
A. shallB. must C. may D. can
【解析】由答語(yǔ)“I’m not sure”可以推測(cè)說(shuō)話(huà)者的語(yǔ)氣不肯定,故答案選【C】 。
May / Might it be cloudy tomorrow ?(×)
Can / Could it be cloudy tomorrow ?(√)3. must的否定式是can’t / couldn’t
“must+動(dòng)詞原形”對(duì)目前的情況進(jìn)行推測(cè)時(shí)以及用must+be+-ing形式對(duì)目前正在發(fā)生的情況進(jìn)行推測(cè)時(shí),表示“一定正在……”。
She must be waiting for us now .
三、情態(tài)動(dòng)詞 + have done的用法
“情態(tài)動(dòng)詞 + have done” 表示對(duì)過(guò)去情況的推測(cè)或估計(jì),是歷年高考的熱點(diǎn)。
1. should (ought to) have+過(guò)去分詞
表示過(guò)去應(yīng)該做而(實(shí)際)沒(méi)有做的事情,含有責(zé)備或遺憾的語(yǔ)氣,意為“本應(yīng)該……”。其否定形式為“should not /ought not to have + 過(guò)去分詞”,其否定式表示某種行為不該發(fā)生但卻發(fā)生了。
— I’m sorry. I________ at you the other day.(08’江蘇卷)
— Forget it. I was a bit out of control myself.
A. shouldn’t shout
B. shouldn’t have shouted
C. mustn’t shout
D. mustn’t have shoutedKey:【B】
2. needn’t have+過(guò)去分詞
表示過(guò)去沒(méi)有必要做某事, 但實(shí)際上做了某事。
As you worked late yesterday, you________ have come this morning.
(06’陜西)
A. mayn’tB. can’t
C. mustn’tD. needn’t
【解析】 He needn’t have come,表示“他本沒(méi)有必要來(lái)(實(shí)際卻來(lái)了)”;注意:He didn’t need to come意為“他沒(méi)有必要來(lái)(實(shí)際也沒(méi)來(lái))”;根據(jù)句意,答案應(yīng)選【D】。
3. must have + 過(guò)去分詞
用于肯定句,表示“過(guò)去一定做過(guò)某事”,表示一種很有把握的推測(cè)。注意,對(duì)過(guò)去發(fā)生情況的否定推測(cè)常用can’t / couldn’t have +過(guò)去分詞。
The teacher ________ have thought Johnson was worth it or she wouldn’t have wasted time on him, I suppose.(07’安徽)
A. shouldB. can C. wouldD. must
【解析】本題應(yīng)選D 。本題的前一句說(shuō)明一個(gè)結(jié)果,后一句則表示一個(gè)原因。表示對(duì)過(guò)去發(fā)生情況的否定推測(cè)。
4. may / might have+過(guò)去分詞
表示對(duì)過(guò)去情況的一種不太有把握的可能性推測(cè),表示“可能 / 大概已做了某事…… ”,否定句表示“可能還沒(méi)有……”。
— I can’t find my purse anywhere.
— You _______ have lost it whileshopping.(08’重慶)
A. mayB. can
C. should D. would Key:【A】
5. can / could have+過(guò)去分詞
肯定句表示“過(guò)去本來(lái)可以做某事,但實(shí)際上沒(méi)有做”;否定句表示“不可能已做了某事”;疑問(wèn)句表示“可能 / 也許已做了某事嗎?”。
She _______ have left school, for her bike is still here. (08’天津)
A. can’tB. wouldn’t
C. shouldn’t D. needn’t
Key: 【A】
鞏固性練習(xí):從A、B、C、D中選擇最佳答案。
1. Our house is on the top of the hill, and in winter the winds _______ be pretty cold.
A. need B. can C. mustD. shall
2. I can hear the Browns’ phone bell ringing but no one is answering it; they _______
be at home.
A. wouldB. mightC. needn’t D. can’t
3. Winter is coming; _______ spring be far away?
A. canB. shouldC. will D. must
4. — John, how did your English exam go?
— I thought I _______ , but in fact I came in the top 10% in the class.
A. should have failed
B. couldn’t have failed
C. might have failed
D. mustn’t have failed
5. My English - Chinese dictionary has disappeared. Who_______ have taken it?
A. should B. must
C. couldD. would
6. I _______ have written to him because he would come back as he informed us.
A. couldn’t B. ought to
C. must D. needn’t
7. — I promise that his daughter______ get a nice present on her birthday.
— Will it be a big surprise to her?
A. should B. must
C. would D. shall
8. — I’m sorry that I didn’t turn on the air-conditioner.
— You_______. I didn’t feel a bit cold.
A. didn’t need bother
B didn’t need to bother
C. needn’t have bother
D. needn’t to bother
9. We were looking for you all this morning. You _______ office without a word.
A. mustn’t have left
B. shouldn’t have left
C. couldn’t have left
D. needn’t have left
10. I couldn’t wait for you any longer. I______ , and so I went.
A. must go B. must have gone
C. had to goD. should have gone
11. The best friend a man has in the world _____ turn against him and become his
enemy.
A. shallB. mayC. willD. would
12. —We need a person badly to be in charge of this design.
— _______ the new comer have a try?
A. MustB. WillC. Need D. Shall
13. — It’s so late. Our son _______ be back!
— Don’t worry. I dare say he _______have some extra work to do.
A. can; must B. will; might
C. should; must D. must; may
Keys for reference:
1-5 BDACC6-10 DDBBC
11-13 BDC