2020年高考英语一轮复习 情态动词

2020;2020年高考英语一轮语法复习：情态动词一、情态动词表示说话人的情感态度。它有一定的实在词义（如：能、会、可能、以前、最好、宁愿。），只有谓语特性，必须和其他动词一起构成谓语，（一般来说）在各种人称后都用同样的形式。二、中学阶段常见的情态动词:情态动词Can could may might must will would shall shouldOught to had better would rather可用着情态动词Used to need dare与情态动词相关的短语Be able to have to情态动词的固定谓语结构：情态动词+（不带to）动词不定式形式do例如： +be done+be doingmust +have done+have been done+have been doing注意：ought (to)和used ( to)例外，动词不定式要带上”to”He can speak 5 languages 他会讲五种语言。Why did you return the book to me ? You neednt have done so.你为什么把书还给我呢？其实你没必要。The student may be playing computer game. 这个学生或许在打电脑游戏。Our teacher couldnt have been watching us outside our classroom.我们的老师不可能一直在教室外面监视我们。Our maths teacher ought to be in the office now. 数学老师现在应该在办公室吧。三、情态动词的用法：1Can(过去式could)1）表示能力”能够、会”She can drive ,but she cant ride a bicycle .A blind man can not judge colours.盲人不能判断颜色。Can you give me a lift to the station?Cant you lend me ten dollars ?请你借给我美元吧？2）表示对现在动作或状态进行主观的猜测“可能、会”，或表示惊异，怀疑，不相信等态度，主要用在否定句、疑问句或感叹句中。例如：He cant have a lot of money.他们不会有很多钱。Can the man over there be our headmaster?那边那个人会是我们校长吗？Can it be that it was I ,not he ,who was mistaken ? 难道错的会是我，而不是他吗？Can this be an excuse for not giving them help ？这难道能成为不帮助他们的理由？This cant be true .这不可能是事实。How can you be so careless!你怎么这么粗心！3）表示客观可能性“可能”，可用于肯定句As a human being,anyone can make a mistake.作为人类，任何人都可能犯错误。The temperature can fall to -60C that is 60C below freezing.气温可降至-60，也就是零下60。（一时的特性）4）表示允许“可以”，意思与may 相近，主要用在口语中Can I have a look at your copy of China Daily?我可以看看你的那份中国日报吗？You can/may go now .现在你可以走了。This sort of thing cant go on .这类事再不可继续下去了。5）构成下列特殊句式：（）can not /can never too 或 cannot enough无论怎么也不过分；越越好；非常。One cannot be too careful .越认真越好。I cannot thank you enough .我对你感激不尽。You cant praise him too highly .你怎么表扬他也不过.(他十分出色)（2）cannot help doing /cannot help but do /cannnot but do ”禁不住；不由得；不得不“。I cannot help admiring the picture whenever I look at it .When a close friend dies ,you cannot but feel sad2.could1)表示能力,指的是过去时间In those days few workers could support their family .那时很少有工人能养活家人.I couldnt follow the teacher in class.上课时我听不懂教师的课.2)表示允许,指的是过去时间She asked whether she could take the books out of the reading-room.她问可不可以把书拿出阅览室.3)表示可能,可以指过去时间;也可以指现在时间,表示语气缓和例如:I didnt think the story could be true.我认为那件事不可能是真的.But you mustnt smoke while youre walking around in the bush either . You could start a bush fire.在丛林里走时也不准抽烟.这样可能引起丛林大火.He looks young .He couldnt be over fifty .他看起来很年轻,他不可能超过五十岁.4)比较委婉客气地提出问题或陈述看法,指的是现在时间Could I see your license?我能否看看你的证件?I have a few friends . I could ring to see if theyre free . 我有几位朋友,我可以给他们打电话,看他们是否有空.Can(could)与be able toCan (could)和be able to 都可以表示能力,意思上没有区别.但can 只有现在式和过去式,而be able to 则有更多的形式.例如:No one is able to do it .没人能做这件事.Will you be able to come tonight ?你今晚能来吗?Im sorry I havent been able to answer your letter .对不起我一直没能给你回信.She said she had not been able to come earlier .她说她没有能够来得更早一些.但是,在表示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 或succeeded in doing ,表示经过一番努力，终于能够。例如： 1） Were able to escapeBelow the 11th 2）Managed to escape into the street .Floor， people 3）succeed in escaping11楼以下的人们逃到了大街上。3May1)表示许诺“可以”或询问、说明一件事。注意：回答may 引起的问句时，否定形式用must not /mustnt (禁止)，had better not (最好别)。May not 比明确的表示禁止的must not 较为委婉，一般很少用。例如：May I trouble you with a quesiton?我能打扰一下问你一个问题吗？Could I call you by your first name ?我可以直接称呼你的名字吗？Yes ,you may .行。（98上海高考）People may not pick flowers in this garden .本园花木不得攀折。May I smoke here ?我可以在这儿抽烟吗？- No ,you mustnt .不行。No ,youd better not . 你最好别在这儿抽。2).表示表示主观的的推测“或许”，通常用在肯定句和否定句中。例如：He may be very busy now .他这会儿可能很忙。At present ,there may be some problems .目前可能还存在着一些问题。He may not be at home . 他可能不在家。注意：表示可能性时，cant 语气强表示“不可能”；may not 语气弱，表示“可能不（或许）”。4Might1)表示可以做的事，指的是过去时间He asked if he might look through my album. 他问可不可以翻翻我的影集。I asked if I might called on her . 我问她我是否可以去拜访她。2）表示口气比较婉转客气，指的是现在时间Might I ask for a photograph of your baby?我可否要一张你宝宝的照片？I wonder if I might borrow some coffee. 不知可否向你借点咖啡。3）表示可能发生的事，可以指过去时间；也可以指现在时间，但表示语气更加不肯定She was afraid they might not like the idea . 她担心他们可能不赞成这个主意。They might have a lot of work to do now but I m not sure. 他们现在可能有很多事要做，不过我下肯定。5Must1)表示必须要做的事We mustnt move someone if they are badly hurt . 如果一个人受了重伤，你一定不要挪动他。注意：在回答由must 引起的问句时，如果是否定回答，不能用mustnt ,而要用neednt 或dont have to ,因为mustnt 是“不准、禁止”的意思。- Must we send in our plan this week ?我们这周必须交上计划吗？-Yes ,you must .是的，必须交。-No,you neednt ./No,you dont have to .不，不用交。2）表示猜测，意为“想必，准是，一定”，只用于肯定句中This must be your room . 这一定是你的房间了You must be joking . 你一定是在开玩笑Look at his new car. He must have a lot of momey . 看他那辆新车，他准是有很多钱。3)表示讨厌情绪“偏偏”I am sleeping when you must turn your radio on.注意：Have to 表示“必须”，“不得不”，在这个意义上与must 很接近，但must 表示的是说话人的主观看法，而 have to 表示的却是客观需要。另外， have to 比must 有更多的形式。You must be back by ten. 到十点钟你必须回来。（命令或叮嘱）You have to be back by ten . 到十点钟你得回来。（客观需要）We had to go home on foot . 我们不得不走回家。Well have to reconsider the whole thing . 这一切我们将不得不重新考虑。6Should 和 ought to “应该”1)表示应该做的事，should 和 ought to 一般可以通用。但ought to 语气更强些，强调“有责任，有义务做”或“按道理应该如何”；should 含有“劝告、建议”的语气，即“按我的想法应该如何”。试比较- Ill start the work tomorrow .我明天开始这工作。-think you should start at once .我想你应当立刻开始。-Ill start the work tomorrow . 我明天开始这工作。-No , you ought to start at once . 不行，你得立即开始。2）表示推测，意为“想必一定，照说应该，估计”。Should 和 ought to 在这一意义上含义比must 弱。试比较Mr Black must be home by now . 布莱克先生现在一定到家了。（肯定）Mr Black ought to (should )be home by now . 布莱克先生估计是到家了。（不能肯定）7Shall1) 用于第一、三人称，构成疑问句，表示征求对方意见或请求指示Shall I open the window ? 我打开窗户好吗？Shall we sit here ?我们坐这儿好吗？Shall the boy wait outside ?(=Do you want the boy to wait outside ?)让那男孩在外面等吗？）用于第二、三人称，表示说话人的意愿，有“命令、警告、威胁、强制、允诺、决心”等意思You shall do as I say . 按我说的做。（命令）Tell him that he shall have the book tomorrow . 告诉他他明天可以拿到那本书。（允诺）If you children dont do as I tell you ,you shall not go to the party . 如果你们这些孩子不按我的话去做，你们就不能去参加晚会。（威胁）You shall be sorry for what you did . 对你的所作所为你会感到后悔的。（警告）Nothing shall stop us from carrying out this plan . 什么也不能阻止我们实现这项计划。（决心）8Will 1)表示“意志，意愿”，可用于多种人称I will do anything for our souldiers .我愿意为我们的战士做任何事。Who will go with me ? 谁愿意和我去？If you will read the book , I will lend it to you . 如果你愿意读这本书，我会把它借给你。注意：从句中的will 是情态动词 ，表示“意愿”；主句中的will 是助动词，帮助构成将来时。2）will 在疑问句中用于第二人称，表示询问对方的意愿或向对方提出请求Will you open the door for me ,please ? 请你为我打开门好吗？Pass me the glass ,will you ? 递给我杯子，好吗？有时，这种句子也可由wont you have a little more rice ? 再来一点米饭好吗？Wont you come over ? 你要不要过来一下？3）表示某种倾向或习惯性动作，意为“总是会，老是，就是”；否定结构意为“不肯、不能”。这种用法并不指将来时间，因此，不能与表示将来时间的状语连用Some birds will fly south when winter comes . 冬天一到，有些鸟就要飞往南方。Boys will be boys . They are always naughty. 孩子就是孩子，他们总是很顽皮。Whats the matter with the door? It wont lock . 这门怎么回事？门就是锁不上。9Would1) 是will 的过去式，表示过去时间的“意志、意愿”，可用于多种人称They said that they would help us . 他们说愿意帮助我们。I promised that I would do my best . 我答应会尽我所能的。2）would 指的是现在时间，表示说话人的意愿或向对方提出请求，语气比will 婉转。也可表示委婉地提出看法、请求、建议等I would like to have a try . 我想试试。Would you like me to carry it for you ? 我帮你拿这个好吗？Im afraid the journey would be too expensive . 恐怕这次旅行费用太贵了。That would be kind of you . 你太好了。3）表示反复发生的动作或过去的一种倾向He told me the box wouldnt open . 他告诉我盒子就是打不开。10 .used to在肯定句中，used to 表示过去（曾经）的动作或状态，二现在“已不”.I used to get along very well with my cousin and we used to be very good friends . 我过去同我的表弟相处得很好，我们曾经是好朋友。I used to live in Nanjing ,but now I live in Shanghai . 我过去住在南京，现在住在上海。在疑问句或否定句中，可以有两种形式。Used you to go to the same school?Did you use to go to the same school? 你们曾经就读于同一所学校吗？I usednt to smoke .I didnt use to smoke . 我过去不抽烟。在反意问句或简略回答中，也有两种形式。John used to be a policeman ,didnt he ?John used to be a policeman ,use (d )nt he ?约翰过去是个警察，是吗？Did you use to take a walk in the morning ?你过去常常早晨散步吗？Used you to go to school in Australia ? 你曾经在澳大利亚念过书吗？Yes ,I did ,Yes ,I used to . 念过。Used to 常用来表示表示已不复存在的过去的习惯，侧重与现在的对比，而would 用来表示过去反复发生的动作。He would go to that bookstore when he was at college. 他在上大学时经常去那个书店。11 NeedNeed 作为情态动词，主要用于否定句，疑问句及表示疑问的从句中。Need he do it all at once ? 他需要马上做这件事吗？Why need you go today ?为什么你今天需要去？I wonder if I need bring my computer .我想知道我是否需要带上电脑。注意：回答由need 引起的问句时，肯定回答一般用must ,否定回答时用needn.-Need I give you the book ?我需要给你这本书吗？ -Yes ,you must .是的，你必须。-No ,you neednt .不，你不必。另外，need 用作及物动词，和不定式连用，可用于各种结构。Does he need to know it ?他需要知道这件事吗？You dont need to do it yourself .这事你不必亲自做。The question needs to be discussed .这问题需要讨论。在个别情况下，need 作为及物动词和情态动词的句子结构在意思上略有差别。He doesnt need to be told .不必告诉他了（他已经知道了）。He neednt be told . 勿需告诉他（告诉他没好处）。12. Dare(dared )Dare 及其过去式dared 作为情态动词，主要用于疑问句、否定句及条件状语从句中。Dare you go home alone ?你敢一个人回家吗？She dare not say what she thinks .她不敢说出她的想法。No one dared speak of it .没有人敢谈这件事。Ill support you if you dare do it .如果你敢做我就支持你。除了在I dare say 这种习惯用语中，dare 在肯定结构中用作情态动词的情形是很少的。If you die ,who will get your money ?如果你死了，谁会得到你的钱呢？I dare say my uncle will.我敢说就是叔父。Dare 还可以作及物动词，跟不定式，用于各种结构。We must dare to act .我们要敢干。I wonder how he dared to say such a thing . 我奇怪他怎么敢说这样的话。I did not dare (to )look up .我不敢抬头看。They do not dare (to )speak .他们不敢讲话。否定句中to 可以省略。四、情态动词后的某些动词(不定式)形式情态动词must表示主观揣测时只能用在肯定的陈述句中，后面可跟have done和be doing.1）情态动词must 后跟have done，表示主观上对过去情况的一种肯定揣测，不能用否定形式-Why isnt he here ?他为什么还未到。-He must have missed the train.他肯定是没赶上火车。Dr Manette realized that the sister must have been very badly treated .曼奈特医生意识到这位姐姐准是惨遭虐待。2）Must 后跟be doing，意为想必（一定）正在They must be waiting for us .Lets hurry .他们一定在等我们了，快点走2Can/could用来表推测常用在疑问句和否定句中，后可跟be doing和have done。1）在否定句中Cant 后跟be doing，意为不会正在He cant be telling the truth .他说的不可能是真话）在疑问句中The light is still on .Can (Could )he still be working ? 灯还亮着，他会是还在工作吗？3）Cant /couldnt 后跟have been doing, 意为想必不可能一直在进行The guards couldnt have been watching very carefully . 卫兵不可能一直进行严密的监视的4）cant 或couldnt 后跟动词的完成式，表示对过去情况的否定揣测。疑问式也由can 或could 后跟have done构成He cant have finished the work so soon.这项工作他不可能完成得这样快。She passed me in the street without speaking .She couldnt have seen me .她没跟我说话就从我身边过去了，她不可能看到我。Where can (could )he have gone ?他会到哪里去了呢？5）could 后跟have done，表示“（那时）本来可以，差点就要”-We could have walked to the station ;it was so near .我们本来可以走着去车站，路这么近。-es .A taxi wasnt at all necessary .是的，没必要坐出租车。We didnt go out last night .We could have gone to the cinema but we decided to stay at home .昨天晚上我们没出去。我们差点就要去看电影了，但又决定待在家里。3. may/ might后可跟have done和be doing表示人们的主观推测。1）may或might 后跟have done，表示对过去可能发生的事进行推测。用might 表示怀疑或更加不肯定，意为“本来可能，简直可以，可能已了，说不定已了，不一定都是虚拟语气，也许是事实用于肯定和否定句式You may have learnt the news . 你们可能知道这个消息了He may not have heard his name called .他或许没听见叫他的名字Sorry Im late .I might have turned off the alarm clock and gone back to sleep again .对不起我迟到了我可能把闹钟关闭了，然后又睡着了2）May /might 后跟be doing，意为可能正在At the moment she may be playing with her friends .这时她可能在和朋友玩呢They are not in the room .They might （could） be working in the field .他们没在房里，可能正在地里干活呢注意：（简单小结）1）情态动词must ,can/could ,may /might 都可以用来对事情进行推测。Must 表推测时只能用于肯定句，是对现在或过去的事情进行的推测，不能表对将来事情的推测，证据非常肯定，译为“一定can/could 表推测时一般用于否定句或疑问句，也是对现在或过去的事情进行推测，但could 偶尔可用于肯定推测May /might 表推测时一般用于肯定句，可对现在、过去或将来的事情进行推测，语气不很肯定，译为“可能。”2）情态动词must ,can/could ,may /might 表推测句子的反义问句的构成。要先将情态动词去掉按照常规句子的方式进行变换。例如：He must be working in the office now ,isnt he?Tom may have missed the bus again,hasnt he?Jack cant have arrived this morning,did he?4Should 或ought to 后跟have done，表示过去本应该做某事却没有做We ought to have given you more help .我们本应该给你们更多帮助的。You shouldnt have done that .你们本不应该做那件事的。There was a lot of fun at yesterdays party .You ought to have come ,but why didnt you ?昨天的舞会非常有趣。你本应该来的，为什么你不来呢？5neednt 后跟have done，表示过去本来没有必要做某事，但实际上却做了You neednt have told them that . 你本可不必告诉他们的You neednt have gone there yesterday .昨天你本来没必要去那儿的He didnt need to worry.他不必担心（是否担心，我们不知道）He neednt have worried .他本不必担心（不必做的事情已经做了）真题演练 Theres no light on -they_be at home .A. cant B. mustnt C. neednt D. shouldnt解析：对现在事实的否定猜测，故A2. If it were not for the fact that she _sing .I would invite her to the party.A. couldnt B. shouldnt C. cant D. might not解析：在此处cant表示不具备某种能力（不会） 故C3. -Must he come to sign this paper himself ?-Yes ,he _.A. need B. must C. may D. will解析：回答must的一般疑问句若肯定用yesmust 故B4. -ay I smoke here ?-If you_,choose a seat in the smoking section.A. should B. could C. may D. must解析：本句must 表示“你一定要的话” 故D5. We _have proved great adventurers ,but we have done the greatest march ever made in the past ten years .A. neednt B. may not C. shouldnt D. mustnt解析：May not have done ,可能没能做某事，故B6. Some aspects of a pilots job _be boring ,and pilots often _work at inconvenient hours .A. can; have to B. may ;can C. have to ;may D. ought to; must解析：Can表示“有某种可能性”；have to比暗示客观上“不得不”故A7 The weather turned out to be fine yesterday .I _the trouble to carry my umbrella with me .A. should have taken B. could have taken C. neednt have taken D. mustnt have taken解析：neednt have done意为“本不需要做而做了” 故C8.hats the name ?-Khulaifi._I spell that for you?A. Shall B. Would C. Can D. Might解析：Shall用于第一人称，表示征求意见 故A