内容正文:
►专题04 情态动词、助动词
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考点
精讲
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情态动词
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考点01 情态动词的语法特征
1) 情态动词不能表示正在发生或已经发生的事情,只表示期待或估计某事的发生。
2) 情态动词除ought 和have 外,后面只能接不带to 的不定式。
3) 情态动词没有人称,数的变化,即情态动词第三人称单数不加-s。
4) 情态动词没有非谓语形式,即没有不定式,分词,等形式。
常见的情态动词有:can (could) ,may (might), must ,shall (should), will (would), dare (dared) , need等,另外,have to、had better也当作情态动词使用。情态动词后面必须加动词的原形。
5)情态动词的回答方式
问句
肯定回答
否定回答
Need you…?
Yes, I must.
No, I needn't
Must you…?
No, I don't have to.
6)带to 的情态动词
带to 的情态动词有:ought to, have to, used to, 它们的疑问、否定形式应予以注意:
Do they have to pay their bill before the end of the month? 他们必须在月底前付帐单吗?
She didn't use to play tennis before she was fourteen.在她十四岁前,她不会打网球。
You ought not to have told her all about it.你不应该告诉他所有这件事。
Ought he to see a heart specialist at once.?
【说明】ought to 本身作为情态动词使用。其他的词作为实义动词使用,变疑问,否定时,须有do 等助动词协助。
考点02 情态动词基本用法
1、can 和be able to
1)can/could 表示能力;可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。例如:
They will be able to tell you the news soon. 他很快就能告诉你消息了。
2)只用be able to的情况:
a. 位于助动词后。
b. 情态动词后。
c. 表示过去某时刻动作时。
d. 用于句首表示条件。
e. 表示成功地做了某事时,用was/were able to,不能用could。例如:
He was able to flee Europe before the war broke out. = He managed to flee Europe before the war broke out.他在战争爆发之前逃离欧洲。
注意:could有时不表示时态
1)提出委婉的请求,(注意在回答中不可用could)。例如:
--- Could I have the television on? 我能看电视吗?
--- Yes, you can. / No, you can't. 可以/不可以。
2)在否定句、疑问句中表示推测或怀疑。例如:
He couldn't be a bad man. 他不大可能是坏人。
2、may和might
表示允许或请求;表示没有把握的推测。例如:
He might be at home. 他可能在家。
注意:might 表示推测时,不表示时态,只是可能性比may 小。
3、have to和must
1)两词都是'必须'的意思,have to 表示客观的需要,must 表示说话人主观上的看法,既主观上的必要。例如:
My brother was very ill, so I had to call the doctor in the middle of the night. 弟弟病得很厉害,我只得半夜里把医生请来。(客观上需要做这件事)
He said that they must work hard. 他说他们必须努力工作。(主观上要做这件事)
2)have to有人称、数、时态的变化,而must只有一种形式。
He had to look after his sister yesterday. 他昨晚只得照顾他姐姐。
3)否定结构中:don't have to表示"不必",mustn't表示"禁止"。例如:
You don't have to tell him about it. 你不一定要把此事告诉他。
You mustn't tell him about it. 你不得把这件事告诉他。
4、must表示推测
1)must用在肯定句中表示较有把握的推测,意为"一定"。
You have worked hard all day. You must be tired. 你辛苦干一整天,一定累了。(对现在情况的推测判断)
He must be working in his office. 他一定在办公室工作呢。
比较:He must be staying there. 他现在肯定在那里。
He must stay there. 他必须呆在那。
2)否定推测用can't。例如:
If Tom didn't leave here until five o'clock, he can't be home yet. 如果汤姆五点才离开这儿,他此时一定还未到家。
5、should 和ought to
表示"想必一定,按理应该"的意思。例如:
I ought to be able to live on my salary. 靠我的薪水,想必也能维持了。
They should be there by now, I think. 现在他们该到那儿了。
6、had better表示"最好",相当于一个助动词,它只有一种形式,它后面要跟动词原形。
It is pretty cold. You'd better put on my coat. 天相当冷。你最好穿上我的外套。
She'd better not play with the dog. 她最好不要玩耍那条狗。
7、would rather表示"宁愿"
would rather do
would rather not do
would rather… than… 宁愿…而不愿。
I would rather stay here than go home. = I would stay here rather than go home. 我宁愿呆在这儿,而不愿回家。
8、will和would
1)would like;would like to do = want to 想要,为固定搭配。例如:
Would you like to go with me? 想和我一块去吗?
2)Will you…? Would you like…? 表示肯定含义的请求劝说时,疑问句中一般用some, 而不是any。例如:
Would you like some cake? 吃点蛋糕吧。
3)否定结构中用will,一般不用would, won't you是一种委婉语气。
Won't you sit down? 你不坐下吗?
9、need和dare
这两词既可做实义动词用,又可做情态动词用。作为情态动词,两者都只能用于疑问句,否定句和条件句。need
作实义动词时后面的不定式必须带to,而dare作实义动词用时, 后面的to 时常可以被省略。
1) 实义动词:need(需要, 要求) need + n. / to do sth
2) 情态动词:need,只用原形need后加do,否定形式为need not。例如:
Need you go yet? 你要走了吗?
Yes, I must. / No, I needn't.是的,我要走了/不,不急着走。
考点03 情态动词表推测的用法
1.对现在或将来的推测用“情态动词+动词原形”。
肯定的推测一般用must,should,may (might)或can(could),其中,must的语气最强。意为“肯定”、“准是”、“想必是”;should的语气次之,意为“很可能”、“应该”,指按常理推测;may(migt),can(could)的语气最弱,意为“有时会”、“也许”、“可能”。
否定推测分为两种情况:语气不很肯定时,常用may/might/could not,意为“可能不”、“也许不”;否定语气较强时,则用can't,意为“根本不可能”、“一定不能”,表示惊异、怀疑的感情色彩。
2.对现在或将来正在进行的行为或情况进行推测,用“情态动词 + be doing”。
My sister can't be climbing the tree.
我妹妹不可能在爬树。
He must be waiting for his girlfriend.
他一定在等女朋友。
3.对过去或已发生的行为或情况进行推测,用“情态动词 + have done”。
1)“must + have done”表示对过去事情把握极大的推测,意为“肯定已经”。
They must have left here last night.
他们一定在昨晚就离开这儿了。
2)“may(might) + have done”为把握不大的猜测,意为“可能已经”。
My daughter may/might have arrived in Rome by now.
我女儿现在可能已到达罗马了。
“might + have done”除了表推测,还能表示过去本来可以做而实际并没有做,带有轻微的责备之意。
His proposal might have been refused.
他的建议本该拒绝的。
3)“could + have done”表示未曾实现的想法、能力、选择及可能性等,“本来可以、本来可能”。
He could have given me some clues.
他本可以给我一些线索的。
She could have prevented the car accident.
她本来可以阻止这场车祸的。
We could have taken the lift.
我们本来可以乘电梯的。
The victim should have been seriously injured.
受害人本来可能伤得很重的。
4)“should (ought to) + have done” 表示“本该做而实际上没做”,
“should not(ought not to) + have done” 表示“本不该做实际上却做了”。
I should have been more careful.
我本该更小心点的。
We should have thought of it.
我们本应该想到这一点。
You should not have done such a thing.
你不应该做出这样的事。
5)“needn't + have done”表示"没有需要做可是却做了"。
The train station is close to him. He needn’t have arrived there so early.
火车站离他很近,他没必要那么早就赶到了。
6)“will/would + have done”可表示推测,也可表示与过去事实相反(常用于虚拟语气)。
My cousin will have arrived by now. 我表哥大概已经到了。
I would have told him the truth if he had been friendly to me.
如果他那时对我友好些,我就告诉他真相了。
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助动词
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考点01: 助动词be/being/been - 用于构成进行时态、被动语态和虚拟语气。
现在进行时:am/is/are + 现在分词
被动语态:am/is/are + 过去分词
虚拟语气:be + 过去分词(某些情况下)
考点02:助动词do/does/did主要帮助构成疑问句、否定句及部分倒装以及强调。助动词do/does/did后只能跟动词原形,助动词不能用作实义动词。
疑问句:Do/Does + 主语 + 动词原形
否定句:Do/Does + not + 动词原形
have - 用于构成完成时态。
考点03:助动词have/has/had主要是帮助构成完成时态和完成进行时态。
需注意其构成形式have/has/had done和have/has/had been doing。
现在完成时:have/has + 过去分词
过去完成时:had + 过去分词
[助记]
助动词,用法怪;只当佐料不当菜。
句型变换显身手;常与时态谈恋爱。
have完成be进行,will将来三大块。
加上各自过去式,总共构成六时态。
否定疑问靠它们,过去did,do现在。
一般现在和过去,没有助动也无碍。
第三人单用does,否定疑问照常变。
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考点
反馈
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1.—Why you be talking so loudly while others are studying?
—I’m terribly sorry.
A.shall B.must C.will D.may
【答案】B
【详解】考查情态动词。句意:——别人学习的时候,你为什么非要大声说话?——真的很抱歉。此处考查must的特殊用法,在句中must的意思是“偏偏,非要”,带有一种责备、抱怨的口气。故选B。
2.If you _________ open your mouth to speak, you’ll do better in English.
A.need B.must C.should D.can
【答案】D
【详解】考查情态动词辨析。句意:如果你能开口讲,你的英语会说得更好。A.need需要;B. must 必须;C.should应该; D.can能。根据“open your mouth to speak”可知,这里指“能够”开口讲英语。故选D项。
3.In science, facts should be proved by experiments and research, and we ______ always believe everything we read and hear -- even if it is a great story.
A.can not B.may not C.must not D.should not
【答案】D
【详解】考查情态动词。句意:在科学中,事实应该通过实验和研究来证明,我们不应该总是相信我们读到和听到的一切——即使它是一个伟大的故事。A. can not不能;B. may not可能不会;C. must not禁止;D. should not不应该。根据“always believe everything we read and hear”和常识可知,我们不应该总是相信我们读到和听到的一切。故选D。
4.You know he is not going to let us leave early if we ________ get the work done.
A.can’t B.may not C.shouldn’t D.mustn’t
【答案】A
【详解】考查情态动词辨析。句意:你知道,如果我们不能完成工作,他是不会让我们早退的。A. can’t不能;B. may not可能不;C. shouldn’t不应该;D. mustn’t禁止。根据后文“get the work done”可知,此处表示能力,意为“不能”应用can’t。故选A。
5.There was a lot of fun at yesterday’s party. You ________ have come. Why didn’t you?
A.must B.should C.needn’t D.may
【答案】B
【详解】考查情态动词+have done。句意:昨天的聚会很有趣。你应该来的。你为什么没来呢?A. must have done一定做了;B. should have done本应该做,却没做;C. needn’t have done本不必做;D. may have done可能做了。根据后文“Why didn’t you?”可知本应该来,却没来,应用should have done。故选B。
6.With the help of the new technology, you e-mail your friends by mobile phone.
A.can B.must C.need D.should
【答案】A
【详解】考查情态动词辨析。句意:在新技术的帮助下,你可以用手机给朋友发电子邮件。此处表示在技术的帮助下所达到的某种能力,can意为“能够、可以”,语义相符,故选A。
7.Harry ________ have won the physics competition easily yesterday, but he gave up.
A.could B.might C.would D.must
【答案】A
【详解】考查情态动词。句意:哈利本可以在昨天的物理竞赛中轻松获胜,但他放弃了。结合句意可知,这里想要表达的是本可以而没有做某事应为“could have done”,故选择A项。
8.—Shall I tell Mike about it?
—No, you _______. He’s already been told.
A.mustn’t B.can’t C.needn’t D.don’t
【答案】C
【详解】考查情态动词/助动词。句意:——要我把这件事告诉迈克吗?——不必。他已经知道了。A. mustn’t禁止;B. can’t不能;C. needn’t不必;D. don’t不。根据后文“He’s already been told.”可知是不必告诉迈克了,故选C。
9.This hi-tech equipment ________ in agriculture area, but the fund was insufficient at that time.
A.might have been used B.may be used
C.may have been used D.should be used
【答案】A
【详解】考查情态动词和虚拟语气。句意:这种高科技设备本可以用于农业领域,但当时资金不足。A. might have been used“本可以被应用”;B. may be used“可以被应用”;C. may have been used表示对过去的推测“或许被应用了”;D. should be used“应该被应用”。结合句意可知,此处和过去相反的虚拟语气,使用might have done表示“本可以做而没有做某事”符合句意,故选A项。
10.The experiment of cloning Dolly ________, for it violated the human morality.
A.should be conducted B.should have been conducted
C.shouldn’t be conducted D.shouldn’t have been conducted
【答案】D
【详解】考查情态动词。句意:克隆多利的实验本不应该进行,因为它违反了人类道德。结合句意可知,这里想要表达的是,本不应该做而做了某事,应用“shouldn’t have done”,故选择C项。
11.You ________ the tree to take the photo, for the aerial equipment can help you to shoot the panoramic view of the school.
A.needn’t climb B.couldn’t have climbed
C.needn’t have climbed D.mustn’t have climbed
【答案】C
【详解】考查情态动词。句意:你本不需要爬到树上拍照,因为空中设备可以帮助你拍摄学校的全景。A. needn’t do不必做某事;B. couldn’t have done表对过去的否定推测“不可能做某事”;C. needn’t have done本不需要做某事而做了;D. mustn’t have done否定推测中不存在这种表达。结合句意可知,此处想要表达的是本不需要爬到树上拍照,却做了,故选C项。
12.In my personal opinion, you ________ have done this as soon as you found out he was stealing.
A.should B.could C.might D.would
【答案】A
【详解】考查情态动词。句意:在我个人看来,一旦你发现他在偷东西,你本应该这么做。A. should have done本应该做……,表示过去本应该做某事实际上却没有做;B. could have done可能做了……,表示对过去事情发生可能性的推测;C. might have done可能做了……,表示对过去事情发生可能性的推测;D. would have done就会……,常用于虚拟语气中,表示对过去情况的假设。根据句意,这里表示在过去发现他偷窃的时候就应该这样做,但实际上却没有做,应用should have done。故选A。
13.I didn’t see her in the meeting room this morning. She ________ at the meeting.
A.mustn’t have spoken B.mightn’t have spoken
C.can’t have spoken D.shouldn’t have spoken
【答案】C
【详解】考查情态动词。句意:今天早上我没有在会议室看到她。她不可能在会上发言。结合句意可知,此处要使用对过去所发生的事情的否定推测,应用can’t have done“不可能做了某事”符合句意,A. mustn’t have spoken为不存在的表达;B. mightn’t have spoken可能没发言;D. shouldn’t have spoken本不应该发言。故选择C项。
14.— Tom took away our teacher’s cell phone without being permitted.
— Really? I can’t imagine that he ________ have done such a thing.
A.must B.may C.can D.should
【答案】D
【详解】考查情态动词。句意:——汤姆未经允许拿走了我们老师的手机。——真的吗?我无法想象他会做这样的事。A. must肯定,必须,表示肯定推测或命令,must have done意为“肯定做了……”;B. may可能,表示可能性,may have done意为“可能做了……”;C. can可以,表示能力或允许,can have done常用于否定句中;D. should应该,竟然,表示责任、义务或惊讶之情,should have done意为“本应该做……,竟然做了……”。根据句意,这里是说不能想象汤姆会拿走了老师的手机,表示惊讶,应用should。故选D。
15.Ms Smith _________ have thought Johnson was worth it or she wouldn’t have wasted time on him. I suppose.
A.might B.must C.would D.should
【答案】B
【详解】考查情态动词。句意:史密斯女士一定认为约翰逊是值得的,否则她不会在他身上浪费时间。我想。A. might或许;B. must一定;C. would将会;D. should应该。根据句意可知,对过去的可能性很大的情况进行肯定推测,用must have done“一定……”。故选B。
16._____ your parents ______ you a present for your birthday every year?
A.Does; give B.Are; give C.Do; give D.Are; gives
【答案】C
【详解】考查助动词和一般疑问句。句意:你的父母每年都给你生日礼物吗?本句是一般疑问句,把原句变成陈述句应该是My parents give me a present for my birthday every year. 原句没有be动词,所以一般疑问句式需要用do或does引导。本句主语是your parents,是第三人称复数形式,所以用do引导,do后面的动词give用原形,故选C项。
17.Last week, I _________ my grandfather, because I was busy with the exam.
A.don’t visit B.didn’t visit C.wasn’t visit D.aren’t visit
【答案】B
【详解】考查时态和助动词。句意:上周我没有去看祖父,因为我忙于考试。根据时间last week,可知此处描述过去发生的事情,需要用一般过去时态。本句已经出现了实意动词visit,有实意动词的句子变否定需要在动词前加didn't,故选B项。
18.Only after we received the news that they had arrived safely ______ a sigh of relief.
A.we did breathe B.we breathed C.breathed we D.did we breathe
【答案】D
【详解】考查倒装。句意:只有在我们收到他们安全到达的消息后,我们才松了一口气。Only+状语/状语从句,置于句首时,主句的谓语动词需用部分倒装,即:Only+状语/状语从句+助动词/情态动词/be动词+主语+其它,根据从句谓语动词 received可知,主语谓语动词需用一般过去时,助动词需用did,所以空处需用did we breathe。故选D。
19.Catherine is a very brave girl. She always asks questions in class and ______.
A.neither has Mary B.so has Mary
C.neither does Mary D.so does Mary
【答案】D
【详解】考查部分倒装。句意:Catherine是一个非常勇敢的女孩。她总是在课堂上问问题,玛丽也一样。当前一句是否定句时,表示后者情况与前者一样,需用neither引导的倒装句,其构成为:neither+助动词/情态动词/be动词+主语;若前一句是肯定句时,表示后者情况与前者一样,需用so引导的倒装句,其构成为:so +助动词/情态动词/be动词+主语;由“She always asks questions in class”可知,前一句是肯定句,所以空处需用so引导的倒装句;由前一句谓语动词asks可知,空处谓语动词需用一般现在现在时,主语是Mary,助动词需用does,表示“问问题”。故选D。
20.Sally’s never seen a play in the Shanghai Grand Theatre, ________?
A.hasn’t she B.has she C.isn’t she D.is she
【答案】B
【详解】考查反义疑问句。句意:Sally从来没有在上海大剧院看过一部戏剧,是不是?反义疑问的主句中含有never等否定词,从句用肯定,主句用现在完成时,疑问部分用has she,故选B。
21.Mr.White doesn’t believe that his son could afford to buy a digital camera,________?
A.could he B.couldn’t he C.does he D.doesn’t he
【答案】C
【详解】考查反意疑问句。怀特先生不相信他的儿子能买得起一台数码照相机,对吗?根据句子结构可知,这句话考查反意疑问句。句子陈述部分是宾语从句,反意疑问句部分要依据主句的主语和谓语动词的结构来判断。主句谓语是实义动词“believe”,反意疑问句部分要用到助动词do。又因为陈述句主句的主语是第三人称“Mr.White”,而且是一般现在时的否定句,有助动词does,所以,反意疑问句部分要用助动词的肯定形式+主语的结构。故选C项。
22.Nowadays many teenagers often take their parents’ love for granted. Seldom________ what they should do in return.
A.do they think B.they think C.did they think D.think they
【答案】A
【详解】考查部分倒装句结构。句意:当今社会,许多青少年把父母对他们的爱当成是理所当然。他们几乎都没有考虑过应该做什么去回报父母。Seldom是否定副词“几乎不”的意思,放在句首时,主句谓语要部分倒装,即把谓语里面的助动词、情态动词或be动词提到主语前面。根据句意,这句话应该是一般现在时,谓语是实义动词think,主语是复数代词they,所以倒装时要加助动词do,并将其提到主语的前面,所以应该填do they think。故选A项。
23.Going to the dentist's ________ not necessarily have to be ________ awful experience.
A.do; an B.does; the C.do; / D.does; an
【答案】D
【详解】考查主谓一致和冠词。句意:去看牙医并不一定是一次可怕的经历。“Going to the dentist's ”是动名词做主语,谓语要用单数形式,因此使用助词does,experience是“经历”意思时,是可数名词,此处表示泛指,用不定冠词。awful是以元音开头,用an修饰。故选D。
24.The percentage of students at high schools who ________ newly diagnosed with depression ________not dropped significantly.
A.was; has B.were; has C.was; have D.were; have
【答案】B
【详解】考查主谓一致。句意:最近被诊断患有抑郁症的高中生的比例还没有显著下降。第一空为定语从句中谓语动词被动态;定语从句谓语动词的形式由先行词单复数决定,先行词students at high schools是复数形式,故be动词用复数,且动作发生在过去,用一般过去时复数形式were;第二空为主句谓语动词现在完成时助动词have的选择,主语the percentage是单数,故助动词用三单形式has。故选B项。
25.He ______ to go shopping with me, because he has a lot of homework to do.
A.isn’t want B.don’t wants C.doesn’t want D.doesn’t wants
【答案】C
【详解】考查助动词和否定。句意:他不想和我一起去购物,因为他有很多作业要做。短语want to do sth.“想要做某事”,此处是谓语动词,表示否定要用助动词,由主语为He可知,助动词用doesn't,后接动词原形。故选C项。
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►专题04 情态动词、助动词
(
考点
精讲
)
(
情态动词
)
考点01 情态动词的语法特征
1) 情态动词不能表示正在发生或已经发生的事情,只表示期待或估计某事的发生。
2) 情态动词除ought 和have 外,后面只能接不带to 的不定式。
3) 情态动词没有人称,数的变化,即情态动词第三人称单数不加-s。
4) 情态动词没有非谓语形式,即没有不定式,分词,等形式。
常见的情态动词有:can (could) ,may (might), must ,shall (should), will (would), dare (dared) , need等,另外,have to、had better也当作情态动词使用。情态动词后面必须加动词的原形。
5)情态动词的回答方式
问句
肯定回答
否定回答
Need you…?
Yes, I must.
No, I needn't
Must you…?
No, I don't have to.
6)带to 的情态动词
带to 的情态动词有:ought to, have to, used to, 它们的疑问、否定形式应予以注意:
Do they have to pay their bill before the end of the month? 他们必须在月底前付帐单吗?
She didn't use to play tennis before she was fourteen.在她十四岁前,她不会打网球。
You ought not to have told her all about it.你不应该告诉他所有这件事。
Ought he to see a heart specialist at once.?
【说明】ought to 本身作为情态动词使用。其他的词作为实义动词使用,变疑问,否定时,须有do 等助动词协助。
考点02 情态动词基本用法
1、can 和be able to
1)can/could 表示能力;可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。例如:
They will be able to tell you the news soon. 他很快就能告诉你消息了。
2)只用be able to的情况:
a. 位于助动词后。
b. 情态动词后。
c. 表示过去某时刻动作时。
d. 用于句首表示条件。
e. 表示成功地做了某事时,用was/were able to,不能用could。例如:
He was able to flee Europe before the war broke out. = He managed to flee Europe before the war broke out.他在战争爆发之前逃离欧洲。
注意:could有时不表示时态
1)提出委婉的请求,(注意在回答中不可用could)。例如:
--- Could I have the television on? 我能看电视吗?
--- Yes, you can. / No, you can't. 可以/不可以。
2)在否定句、疑问句中表示推测或怀疑。例如:
He couldn't be a bad man. 他不大可能是坏人。
2、may和might
表示允许或请求;表示没有把握的推测。例如:
He might be at home. 他可能在家。
注意:might 表示推测时,不表示时态,只是可能性比may 小。
3、have to和must
1)两词都是'必须'的意思,have to 表示客观的需要,must 表示说话人主观上的看法,既主观上的必要。例如:
My brother was very ill, so I had to call the doctor in the middle of the night. 弟弟病得很厉害,我只得半夜里把医生请来。(客观上需要做这件事)
He said that they must work hard. 他说他们必须努力工作。(主观上要做这件事)
2)have to有人称、数、时态的变化,而must只有一种形式。
He had to look after his sister yesterday. 他昨晚只得照顾他姐姐。
3)否定结构中:don't have to表示"不必",mustn't表示"禁止"。例如:
You don't have to tell him about it. 你不一定要把此事告诉他。
You mustn't tell him about it. 你不得把这件事告诉他。
4、must表示推测
1)must用在肯定句中表示较有把握的推测,意为"一定"。
You have worked hard all day. You must be tired. 你辛苦干一整天,一定累了。(对现在情况的推测判断)
He must be working in his office. 他一定在办公室工作呢。
比较:He must be staying there. 他现在肯定在那里。
He must stay there. 他必须呆在那。
2)否定推测用can't。例如:
If Tom didn't leave here until five o'clock, he can't be home yet. 如果汤姆五点才离开这儿,他此时一定还未到家。
5、should 和ought to
表示"想必一定,按理应该"的意思。例如:
I ought to be able to live on my salary. 靠我的薪水,想必也能维持了。
They should be there by now, I think. 现在他们该到那儿了。
6、had better表示"最好",相当于一个助动词,它只有一种形式,它后面要跟动词原形。
It is pretty cold. You'd better put on my coat. 天相当冷。你最好穿上我的外套。
She'd better not play with the dog. 她最好不要玩耍那条狗。
7、would rather表示"宁愿"
would rather do
would rather not do
would rather… than… 宁愿…而不愿。
I would rather stay here than go home. = I would stay here rather than go home. 我宁愿呆在这儿,而不愿回家。
8、will和would
1)would like;would like to do = want to 想要,为固定搭配。例如:
Would you like to go with me? 想和我一块去吗?
2)Will you…? Would you like…? 表示肯定含义的请求劝说时,疑问句中一般用some, 而不是any。例如:
Would you like some cake? 吃点蛋糕吧。
3)否定结构中用will,一般不用would, won't you是一种委婉语气。
Won't you sit down? 你不坐下吗?
9、need和dare
这两词既可做实义动词用,又可做情态动词用。作为情态动词,两者都只能用于疑问句,否定句和条件句。need
作实义动词时后面的不定式必须带to,而dare作实义动词用时, 后面的to 时常可以被省略。
1) 实义动词:need(需要, 要求) need + n. / to do sth
2) 情态动词:need,只用原形need后加do,否定形式为need not。例如:
Need you go yet? 你要走了吗?
Yes, I must. / No, I needn't.是的,我要走了/不,不急着走。
考点03 情态动词表推测的用法
1.对现在或将来的推测用“情态动词+动词原形”。
肯定的推测一般用must,should,may (might)或can(could),其中,must的语气最强。意为“肯定”、“准是”、“想必是”;should的语气次之,意为“很可能”、“应该”,指按常理推测;may(migt),can(could)的语气最弱,意为“有时会”、“也许”、“可能”。
否定推测分为两种情况:语气不很肯定时,常用may/might/could not,意为“可能不”、“也许不”;否定语气较强时,则用can't,意为“根本不可能”、“一定不能”,表示惊异、怀疑的感情色彩。
2.对现在或将来正在进行的行为或情况进行推测,用“情态动词 + be doing”。
My sister can't be climbing the tree.
我妹妹不可能在爬树。
He must be waiting for his girlfriend.
他一定在等女朋友。
3.对过去或已发生的行为或情况进行推测,用“情态动词 + have done”。
1)“must + have done”表示对过去事情把握极大的推测,意为“肯定已经”。
They must have left here last night.
他们一定在昨晚就离开这儿了。
2)“may(might) + have done”为把握不大的猜测,意为“可能已经”。
My daughter may/might have arrived in Rome by now.
我女儿现在可能已到达罗马了。
“might + have done”除了表推测,还能表示过去本来可以做而实际并没有做,带有轻微的责备之意。
His proposal might have been refused.
他的建议本该拒绝的。
3)“could + have done”表示未曾实现的想法、能力、选择及可能性等,“本来可以、本来可能”。
He could have given me some clues.
他本可以给我一些线索的。
She could have prevented the car accident.
她本来可以阻止这场车祸的。
We could have taken the lift.
我们本来可以乘电梯的。
The victim should have been seriously injured.
受害人本来可能伤得很重的。
4)“should (ought to) + have done” 表示“本该做而实际上没做”,
“should not(ought not to) + have done” 表示“本不该做实际上却做了”。
I should have been more careful.
我本该更小心点的。
We should have thought of it.
我们本应该想到这一点。
You should not have done such a thing.
你不应该做出这样的事。
5)“needn't + have done”表示"没有需要做可是却做了"。
The train station is close to him. He needn’t have arrived there so early.
火车站离他很近,他没必要那么早就赶到了。
6)“will/would + have done”可表示推测,也可表示与过去事实相反(常用于虚拟语气)。
My cousin will have arrived by now. 我表哥大概已经到了。
I would have told him the truth if he had been friendly to me.
如果他那时对我友好些,我就告诉他真相了。
(
助动词
)
考点01: 助动词be/being/been - 用于构成进行时态、被动语态和虚拟语气。
现在进行时:am/is/are + 现在分词
被动语态:am/is/are + 过去分词
虚拟语气:be + 过去分词(某些情况下)
考点02:助动词do/does/did主要帮助构成疑问句、否定句及部分倒装以及强调。助动词do/does/did后只能跟动词原形,助动词不能用作实义动词。
疑问句:Do/Does + 主语 + 动词原形
否定句:Do/Does + not + 动词原形
have - 用于构成完成时态。
考点03:助动词have/has/had主要是帮助构成完成时态和完成进行时态。
需注意其构成形式have/has/had done和have/has/had been doing。
现在完成时:have/has + 过去分词
过去完成时:had + 过去分词
[助记]
助动词,用法怪;只当佐料不当菜。
句型变换显身手;常与时态谈恋爱。
have完成be进行,will将来三大块。
加上各自过去式,总共构成六时态。
否定疑问靠它们,过去did,do现在。
一般现在和过去,没有助动也无碍。
第三人单用does,否定疑问照常变。
(
考点
反馈
)
1.—Why you be talking so loudly while others are studying?
—I’m terribly sorry.
A.shall B.must C.will D.may
2.If you _________ open your mouth to speak, you’ll do better in English.
A.need B.must C.should D.can
3.In science, facts should be proved by experiments and research, and we ______ always believe everything we read and hear -- even if it is a great story.
A.can not B.may not C.must not D.should not
4.You know he is not going to let us leave early if we ________ get the work done.
A.can’t B.may not C.shouldn’t D.mustn’t
5.There was a lot of fun at yesterday’s party. You ________ have come. Why didn’t you?
A.must B.should C.needn’t D.may
6.With the help of the new technology, you e-mail your friends by mobile phone.
A.can B.must C.need D.should
7.Harry ________ have won the physics competition easily yesterday, but he gave up.
A.could B.might C.would D.must
8.—Shall I tell Mike about it?
—No, you _______. He’s already been told.
A.mustn’t B.can’t C.needn’t D.don’t
9.This hi-tech equipment ________ in agriculture area, but the fund was insufficient at that time.
A.might have been used B.may be used
C.may have been used D.should be used
10.The experiment of cloning Dolly ________, for it violated the human morality.
A.should be conducted B.should have been conducted
C.shouldn’t be conducted D.shouldn’t have been conducted
11.You ________ the tree to take the photo, for the aerial equipment can help you to shoot the panoramic view of the school.
A.needn’t climb B.couldn’t have climbed
C.needn’t have climbed D.mustn’t have climbed
12.In my personal opinion, you ________ have done this as soon as you found out he was stealing.
A.should B.could C.might D.would
13.I didn’t see her in the meeting room this morning. She ________ at the meeting.
A.mustn’t have spoken B.mightn’t have spoken
C.can’t have spoken D.shouldn’t have spoken
14.— Tom took away our teacher’s cell phone without being permitted.
— Really? I can’t imagine that he ________ have done such a thing.
A.must B.may C.can D.should
15.Ms Smith _________ have thought Johnson was worth it or she wouldn’t have wasted time on him. I suppose.
A.might B.must C.would D.should
16._____ your parents ______ you a present for your birthday every year?
A.Does; give B.Are; give C.Do; give D.Are; gives
17.Last week, I _________ my grandfather, because I was busy with the exam.
A.don’t visit B.didn’t visit C.wasn’t visit D.aren’t visit
18.Only after we received the news that they had arrived safely ______ a sigh of relief.
A.we did breathe B.we breathed C.breathed we D.did we breathe
19.Catherine is a very brave girl. She always asks questions in class and ______.
A.neither has Mary B.so has Mary
C.neither does Mary D.so does Mary
20.Sally’s never seen a play in the Shanghai Grand Theatre, ________?
A.hasn’t she B.has she C.isn’t she D.is she
21.Mr.White doesn’t believe that his son could afford to buy a digital camera,________?
A.could he B.couldn’t he C.does he D.doesn’t he
22.Nowadays many teenagers often take their parents’ love for granted. Seldom________ what they should do in return.
A.do they think B.they think C.did they think D.think they
23.Going to the dentist's ________ not necessarily have to be ________ awful experience.
A.do; an B.does; the C.do; / D.does; an
24.The percentage of students at high schools who ________ newly diagnosed with depression ________not dropped significantly.
A.was; has B.were; has C.was; have D.were; have
25.He ______ to go shopping with me, because he has a lot of homework to do.
A.isn’t want B.don’t wants C.doesn’t want D.doesn’t wants
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