(共58张PPT)
情态动词
情态动词
情态动词有一定的意义,但没有人称和数的变化,不能独立使用,它和后面的动词构成谓语.
只作情态动词的 can/could, may/might, ought to, must
可情态可实义的 need, dare/dared
可情态可助动词的 shall/should, will/would
相当于情态动词的 have to, used to
1. can
表示能力 The parrot can speak three languages.
表示允许 Can I borrow the book from the library.
有时会 Shanghai can be very cold in March.
2. can 与 be able to
can 表示能力,
be able to表示经过努力而做成了
某事,相当于manage to do/succeed in doing。搭配各种时态,但不能与could连用。必须人作主语。
3. can/could + have +p.p
1.在否定、疑问句中表示
对过去的可能性猜测
2. 在肯定句中表
“本可以做而未做”
can’t 不能,不可能
1. A computer ______ think for itself; it must be told what to do.
A. can’t B. couldn’t
C. may not D. might not
2. The fire spread through the hotel very quickly but everyone ______ get out.
A. had to B. would
C. could D. was able to
A
D
3. They will ______ run this machine on their own in three months.
A. can B. could C. may D. be able to
D
1. may
表示可能性
表示允许、可以
表示祝愿
might 过去式;语气更委婉
2. may/might + have +p.p
表示对过去动作的推测
“也许是……”
表示许可: may / might, can / could
* might, could 比较委婉, 一般多用于疑问句.
* can, may 表达的语言比较随便.
* 在以could, might 表示征询对方意见
或表示请求时,回答应相应使用can, may.
1. must
1.表示必须、应该
2.偏偏、偏要、硬要、非要(表示与说话
人愿望相反或不耐烦)
3.表示肯定的猜测,但只用于肯定句,
4.而mustn’t 表示“禁止、不准许、不可以”
2. must 、have to
Must表示主观
2.Have to表示客观需求
3.don’t have to 表示没有必要
3. must + have +p.p
must do
对过去事情的肯定猜测。
对现在事情的推测
1.第一、三人称疑问句中表示“请求或
征求对方意见
2.第二、三人称陈述句中
1、表示允诺“会(得到)。
2、表示命令、警告、威胁、决心 。
3、在法律、条约、协定的文件中
表示“义务、规定”
1.(表惊讶、遗憾)竟然、居然
2.(与疑问词why, who, how等连用,表示意外、纳闷、惊讶等)究竟、到底
3.(用于问句,表示询问、征求同意)可以、应该
Should I turn on the light
shall
Should
1、表示意愿、决心或愿望
Will 2、表示请求(用于第二人称)
3.(表示现在的习惯性、倾向性、必然性)
惯于、老是、总是
Will /Would you do… (表请求would 更委婉)表意志,
愿望,决心
need作情态动词,多用于否定句和疑问句。
need没有过去式
用作情态动词
--Need I come /Do I need to come
--Yes, you must. You needn t telephone him now. 你现在不必打电话给他。
用作实义动词
You don t need to do it yourself. 你不必亲自做这件事。 The table needs painting (to be painted.). 桌子需要油漆一下。
dare作情态动词,多用于否定句、疑问句和条件句。dare 有过去式dared
用作情态动词
She dare not go out alone at night.
Dare he cross the river ----No, he daren’t
用作实义动词
We should dare to give our own opinion.
I dare say he ll come again. 我想他会再来的。
(I dare say…为固定习语“译为我想…、大概…”)
2. 表示否定的情态动词的用法:
mustn’t 不准, 禁止
needn’t 没必要 ( = don’t have to )
can’t 不能; 不可能
may not 不可以; 可能不
shouldn’t 不应该 ( = ought not to )
won’t/ wouldn’t 不愿意
daren’t 不敢
Shall not=shan’t
情态动词在一般疑问句中的回答:
① Can you sing
② May I come in
③ Must I hand in the book now
④ Need I finish it now
Yes, I can.
No, I can’t.
Yes, you may.
No, you mustn’t.
Yes, you must.
No, you needn’t /don’t have to.
Yes, you must.
No, you needn’t.
1. 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
2. Johnny, you ______ play with the knife, you
______ hurt yourself.
A. won’t ; can’t B. mustn’t ; may
C. shouldn’t ; must D. can’t ; shouldn’t
C
B
情态动词表推测
may /might 语气最不肯定,用于肯、否定句“可能”
can 语气肯定,用于感叹,否,疑问句,一般
不用肯定句“可能”
could 较can不确定,也可用于肯定句“可能”
must 语气最肯定,只用于肯定句“一定”
should 表可能性、推论、推测、期待等“按理该、
估计”
情态动词表责备
may/might have done(语气委婉)过去
本可能做…而未做
can/could have done(语气委婉)过去本可能做…而未做
should have done \ ought to have done(语气强烈)过去本应该做…而未做
shouldn’t have done \ ought not to have done 表示过去本不应该做…而做了
needn’t have done(无责备之意)过去
本不必做…却做了
would have done 用在虚拟语气中
表示与过去事实相反之假设的结果,常与if 的条件句连用。
表示推测——情态动词的重要用法.
肯定的推测
可能的推测
否定的推测
疑问的推测
must/should
对将来 对现在 对过去
情态动词
may, might
can’t,
couldn’t
can, could
+ V. + V. + have done
常见must be + be doing
+ V. + V. + have done
+ be doing
可以用not表示“可能不”
+V. + V. + have done
+ be doing
+ V. + V. + have done
+ be doing
1. You must be Mr Smith----I was told to expect you here.
2. He must have known what we wanted.
3. We may have read the same report.
4. He can’t have slept through all that noise.
5. There’s someone outside----who can it be
6. What can they be doing
7. These pills might help to cure your disease.
8. You could be right, I suppose.
情态动词+完成式:
1. must have done
2. may/might have done
3. can’t couldn’t jave done
4. should /ought to have done
5. shouln’t/oughtn’t to have done
6. could have done
7. needn’t have done
8. would rather have done
shall和will的比较
比较内容 肯定句 疑问句
shall 二三人称,表示“威胁”、“警告”、“允诺”的语气 与第一、三人称连用,表示征询对方的意见
Will/would 1)表示“习惯”
2)表示“愿意/望”
3)表示“必然性” 与第二人称连用,表示征询对方的意见
1. If you ________follow my advice, I _____ offer you some help.
2. ______ you meet him right now or ____ he wait outside, sir
will
shall
Will
shall
3. He ______ be punished if he disobeys.
如果他不服从, 就要受到惩罚.
4. We are not going to quarrel at all if you ____
only let me speak.
只要你让我说话, 我们根本就不会吵架.
5. --Sir, ____ he go or stay
--Let him go.
A. will B. shall C. might D. could
shall
will
B
would 和 used to的比较
1、would 主要表示过去一段时间内的某种习惯,常与表示过去的时间状语连用,意为“总要,总是”
used to 主要表示过去存在但是现在已不再存在的习惯,意为“过去常常”。
On Sundays he _______ go to call on the old man when he was young.
I _______ get up late, but now I have got used to getting up very early.
Xiao Li ________ be a model worker. He is now a university student.
would
used to
used to
可兼做行为动词的情态动词:need 、 dare
情态动词 (+动词原形)
行为动词
.
need
dare
1.无人称和数的变化;
2.尤其用于:
*否定句及疑问句中;
*在if/whether之后;
*或与hardly, never,
no one, nobody连用;
3.常以needn’t 和daren’t
的形式出现;
4.dare有其过去时dared.
多用于肯定句;
(sb.) need to do
dare to do
(sth.) need to be
done
(sth.) need doing
I daren’t ask her for a rise. 我不敢请求她加薪.
How did you dare to tell her that
I wonder whether he dare stand up in public.
I don’t know how she dares to wear that dress.
Do you need any help
I wonder whether he need send it immediately.
I need hardly tell you that the work is dangerous.
The garden doesn’t need watering at the moment.
You needn’t finish that work today.
f.
3. 情态动词表示推测的用法
A. 对现在状态和动作的推测
高考题点击:
1. Peter _______ come with us tonight, but he isn’t very sure
yet. (N 1993)
A. must B. may C. can D. will
2. Michael _______ be a policeman, for he is much too short.
(1994上海)
A. needn’t B. can’t C. should D. may
B
B
must 加动词原形表示“必须做”;may 加动词原形表示“可能会做”;can 加动词原形表示“能够做”;can 表示“可能性”时只用在问句和否定句中。该句的关键在于“but he isn’t sure yet”。
needn’t 表示“不必”;can’t 表示“肯定不”;后两个选项与句意差别太大。此句的关键在于 “for he is much too short”.
3. It’s nearly 7:00. Jack ____ be here at any moment. (N 1995)
A. must B. need C. should D. can
4. Johnny, you _______ play with the knife, you _______ hurt
yourself. (N 1996)
A. won’t, can’t B. mustn’t, may
C. shouldn’t, must D. can’t, should
C
B
must + be 表示“肯定会”;need + be 表示 “需要在”;should + 动词原形表示“非常有可能”;can 表示可能性只用在否定和疑问句中。
前句表示“你不能玩刀”,此处的 “不能”并非表示“能力”,而是表示“允许”,所以只能用“mustn’t”;后句表示“可能会伤着你自己”,故用 may。
5. ---- Are you coming to Jeff’s party
---- I’m not sure. I _____ go to the concert instead. ( N 2000)
A. must B. would C. should D. might
6. Mr. Bush is on time for everything. How _____ it be that he
was late for the opening ceremony (2001上海春季)
A. can B. should C. may D. must
D
A
此句的关键在于“I’m not sure”,既然不能肯定,只能是一种“可能性”。
此句的意思为:“Bush 先生总是很守时,他怎么可能在出席开幕仪式时迟到呢?“ can 在否定句或疑问句中表示“可能性”。
7. --- Is John coming by train
--- He should, but he ______ not. He likes driving his car.
(N 2002)
A. must B. can C. need D. may
8. --- I heard they went skiing in the mountains last winter.
--- It _________ true because there was little snow there.
(N 2002北京)
A. may not be B. won’t be
C. couldn’t be D. mustn’t be
D
C
此句的关键是“He likes driving his car.” can 和 may 都可用于否定句中,can’t 表示“根本不可能”,语气很强;may not 表示“也许不可能”,语气较弱。
couldn’t 的语气比 can’t 弱。
B. 对过去动作或状态的推测
Tom ought not to _______ me your secret, but he meant no
harm. (N1993)
A. have told B. tell C. be telling D. having told
2. I told Sally how to get here, but perhaps I _______ for her. (N 1994)
A. had to write it out B. must have written it out
C. should have written it out D. ought to write it out
A
C
ought to 相当于 should;此句的关键是“He meant no harm”,显然指的是过去的事。
should have written 意指“本该写但实际上并没有写”。
3. --- There were already 5 people in the car but they managed to
take me as well.
--- It ________ a comfortable journey. (N 1995)
A. can’t be B. shouldn’t be
C. mustn’t have been D. couldn’t have been
4. Susan_______ written a report like this. (1995上海)
A. can have B. mustn’t have
C. can’t have D. ought to not have
D
C
此句谈论的是过去的经历,故 A、B 不合题意;must 表示判断和推测只能用在肯定句中。
该句的意思为 Susan 不可能写出这样的报告来。ought to have done 的否定式为 ought not to have done。
5. Jack ____ yet, otherwise he would have phoned me. (N 97)
A. mustn’t have arrived B. shouldn’t have arrived
C. can’t have arrived D. needn’t have arrived
6. --- I stayed at a hotel while in New York.
--- Oh, did you You______ with Barbara. (N 1998)
A. could have stayed B. could stay
C. would stay D. must have stayed
C
A
此句的关键是后半句,“otherwise he would have phoned me”,此处为省略了条件句的虚拟语气,表示“如果到了他会打电话给我的”,由此可见,他肯定没到。
7. There was a lot of fun at yesterday’s party. You ____ come,
but why didn’t you (1999上海)
A. must have B. should C. need have D. ought to have
8. I was really anxious about you. You _____ home without a
word. (N 2001)
A. mustn’t leave B. shouldn’t have left
C. couldn’t have left D. needn’t leave
9. Oh, I’m not feeling well in the stomach, I _____ so much
fried chicken just now. (2002上海春季)
A. shouldn’t cut B. mustn’t have eaten
C. shouldn’t have eaten D. mustn’t eat
D
B
C
4. shall; should 的特殊用法
1. It has been announced that candidates ____ remain in their
seats until all the papers have been collected. (2002上海)
A. can B. will C. may D. shall
2. It’s nearly 7:00. Jack _____ be here at any moment. (N 95)
A. must B. need C. should D. can
D
C
该句的意思为:“通知说所有的考生必须坐在位置上直到考卷收完了才能离开。”考生坐在位置上不能用“能够、将要、可以”来表示。而 shall 在第二、三人称里面表示一种“命令、警告、承诺”等。
3. --- When can I come for the photos I need them tomorrow
afternoon.
--- They __________ be ready by 12:00. (N 1998)
A. can B. should C. might D. need
4. You can’t imagine that a well-behaved gentleman _____ be
so rude to a lady. (2001上海)
A. might B. need C. should D. would
B
C
此句应是店主对顾客的承诺。
should 与 how; why 等表示疑问或否定的词连用时,用来表示一种惊奇的心情,意思为“居然、竟然”
5. 情态动词的应答
1. --- Shall I tell John about it
--- No, you ______. I’ve told him already. (N 1994)
A. needn’t B. wouldn’t C. mustn’t D. shouldn’t
2. --- Could I call you by the first name
--- Yes, you__________. (1998上海)
A. will B. could C. may D. might
A
C
此句的关键是“I’ve told him already”,由此可见,你就不必再对他说了。
在回答 “Could I …”这类婉客气的请求时,只能回答“Yes, you can 或 may”。不能用 could 或 might。
3. --- Will you stay for lunch
--- Sorry, _____. My brother is coming to see me. (N 1999)
A. I mustn’t B. I can’t C. I needn’t D. I won’t
4. ---- Write to me when you get home.
---- __________. (2001北京春季)
A. I must B. I should C. I will D. I can
B
C
此句的关键是 “My brother is coming to see me.” 所以我不能在这儿吃饭。
在回答对方的请求或命令时,应该用 “Yes, I will.”而不能使用 would 或 should。
6. 情态动词的其它一些用法
1. I wonder how he _______ that to the teacher. (1996上海)
A. dare to say B. dare saying C. not dare say D. dared say
2. When he was there, he _______ go to that coffee shop at
the corner after work every day. (1996上海)
A. would B. should C. had better D. might
D
A
注意比较 dare 和 need 的两种词性的不同用法。
would 在此处表示过去惯常的动作。
考点诠释:考点一、情态动词基本含义的考查
The fire spread through the hotel very quickly but everyone ______get out.
A. had to B. would C. was able to D. could
解析:考查情态动词的基本含义。had to:不得不; would:表示意愿或过去常常;could倾向于表示经过长期训练而获得的能力;was able to 表示经过努力而能够做到的事或成功地做了某事。因此,答案是C。
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考点诠释
2. 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
解析:can:能够;should:应该,表示责任、义务。Might:可能;need:需要。它们应该在12点前准备好。所以,答案是B。
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考点诠释
3. You can’t imagine that a well-behaved gentleman______be so rude to a lady .
A. might B. need C. should D. would
解析:should 表示说话人感情,如惊奇、愤怒、失
望等。在此句中表示说话人一种惊奇的语气。 句意为
你不可能想象出体面的绅士竟然对一位女士那么粗
鲁。答案是 C。
分析:高考对情态动词基本含义的考查,仍然集中在常用的情态动词上。对常用情态动词的含义,要掌握的既
准确又要全面,特别是shall, should, can, may 四个常用情态动词
的含义较多,不易理解,复习时应当引起重视。
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二、情态动词表示推测的考查
对情态动词表示推测的用法,是高考考查情态动词的一个重要方面。例如:
1. Sorry, I’m late. I ______ have turned off the alarm clock and gone back to sleep again .
A. might B. should C. can D. will
解析:might have done : (过去)可能做过某事;
should have done :本应该做某事。根据本句提
供的情境I’m late 表明说话人可能把闹钟关上了
。答案是:A。
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考点诠释
2. My sister met him at the Grand Theatre yesterday afternoon, so he ______your lecture.
A. couldn’t have attended B. needn’t have attended
C. mustn’t have attended D. shouldn’t have attended
解析:couldn’t have done: (过去)不可能做某事; needn’t have done:本来不必做某事;mustn’t have done:一定未做过某事: shouldn’t have done:本不该做某事。根据提供的情境My sister met him at the Great Theatre表明他不可能参加讲座。答案是:A。
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考点诠释
3. Mr Bush is on time for everything. How
______it be that he was late for the opening
ceremony
A. can B. should C. may D. must
解析:can表示可能性。布什先生按时做一切事.
他怎么可能开幕式迟到呢?答案是:A。
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4.I heard they went skiing in the mountains last winter
—It ______true because there was little snow
there.
A. may not be B. won’t be
C. couldn’t be D. mustn’t be
解析:may not be: 可能不是; won’t be: 不会是;
couldn’t be:不可能是; mustn’t be : 一定不是
根据提供情境there was little snow 说明山里滑雪是件不可能的事,may not 语气不如couldn’t强
。答案是:C。
考点诠释
分析:高考对表示推测的情态动词集中在must, can, could, may, might上,准确掌握它们使用的场合,是解决问题的关键。Must 用于肯定陈述句,表示肯定推测;can, could用于疑问或否定陈述句,表示可能性推测;may, might用于陈述句,表示可能性推测;用于否定陈述句中,can’t (不可能)的语气比may not(可能不)强。此外,还要注意有对过去和对现在两种情况的推测,对过去推测用情态动词+have done ,对现在推测用情态动词+ 动词原形。
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三、情态动词表示虚拟的考查
情态动词+have+过去分词表示与过去事实上相反的情况, 也是高考单项选择题涉及到情态动词的一个重要方面。
1. There was a lot of fun at yesterday’s party. You ______ come, but why didn’t you
A. must have B. should
C. need have D. ought to have
解析:ought to have done 表示本来应该做某事而
实际没做,should do 表示现在应该做某事,与题
中 at yesterday’s party 表示的时间不一致。所以
选D。
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考点诠释
2.I was really anxious about you. You ______home without a word.
A. mustn’t leave B. shouldn’t have left
C. couldn’t have left D. needn’t leave
解析:shouldn‘t have done 表示本来不应该做
而实际上做了。句意为:你不应该不说一句话
就离开家,而实际上是没说一句话就离开家了。
答案是:B。
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考点诠释
3.Oh, I‘m not feeling well in the stomach. I______so much fried chicken just now.
A. shouldn’t eat B. mustn’t have eaten
C. shouldn’t have eaten D. mustn’t eat
解析:该句所表达的意思是刚才我不因该吃那么多炸鸡,而实际上是吃了那么多,可以判断用shouldn’t have eaten. 答案是 C。
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分析:高考对情态动词表示虚拟‘用法,表示与过去事实相反的情况。近几年高考,主要侧重
should (not)have done 这一句式上,表示本来不该做却做了或本来该做却未做的事, 在复习时,还应关注其它几种虚拟形式,如need (not) have
done 表示本来需要做而未做或本来不需要而做的事等等,以做到有备无患。
考点四、情态动词与助动词混合考查
1.Tom ,you didn’t come to the party last night
—I______, but I suddenly remembered I had homework to do .(NMET2007全国卷II,20)
A. had to B. didn’t C. was going to D. wouldn’t
解析:had to:不得不;didn’t:没来;was going to:打算来;wouldn’t:不愿来。句意:——汤姆,昨晚你没来参加舞会吗?——我本打算来,但我突然记起有作业要做。But是关键词,所以答案是:C。
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考点诠释
2.Your phone number again I______quite catch it .
—It’s 86184867.
A. didn’t B. couldn’t C. don’t D. can’t
解析:记住电话号码并非难事,未完全听清楚电话号码并非能力的事,此处只是说没有完全
听清楚电话号码,所以,应选A。
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高考链接
1.(09安徽)29. Some people who don’t like to talk much are not necessarily shy;they just be quiet people.
A. must B. may C. should D. would
【答案】B
【解析】考察情态动词的用法.前半句为” 有些人不喜欢讲很多话未必就是因为害羞,”后半句应该为”他们可能是比较安静的人.”
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高考链接
2,(09北京)25. One of the few things you __ _ say about English people with certainty is that they talk a lot about the weather.
A. need B. must C. should D. can
【答案】D。
【解析】考查情态动词的用法。关于英国人你可以肯定的一点是他们谈论很多的天气。用can表示可以,能够,所以正确答案为:D。不能选C,should是表示责任和义务的。
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高考链接
3.(09重庆卷)32. ---Hi, Tom. Any idea where Jane is
---She in the classroom. I saw her there just now.
A. shall be B. should have been C. must be D. might have been
【答案】C。
【解析】根据语境知道问现在在哪里,而第二句话是指我刚才见到他在教室里,由此可以肯定,她现在一定在教室里,是对现在的肯定推测。
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高考链接
4.(NMET2008山东,24)Thank you for all your hard work last week. I don’t think we ______ it without you.
A. can manage B. could have managed
C. could manage D. can have managed
【解析】根据题干中所给出的时间last week可知我们已经做完了工作,已经完成,故排除A、C两项,再结合could have done表示虚拟语气以及与前面的I don’t think…,故说话者想表达的意思是:离开了你,我们本不可能完成这项工作。故答案为B项。
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高考链接
5.(NMET2007 江苏)—She looks very happy. She ______ have passed the exam.
—I guess so. It’s not difficult after all.
A. should B. could C. must D. might
【解析】句意为:她看上去很高兴,一定是通过了考试。
【答案】C
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高考链接
6. (NMET2008陕西)-What sort of house do you want to have Something big
--Well, it ______ be big--that's not important.
A. mustn't B. needn't C. can't D. won't
【解析】Something big 此处意为:Must it be big 回答者的意思是:房子不必太大—那并不重要。
【答案】B
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