第二部分第九讲情态动词和虚拟语气
情态动词与虚拟语气知识点讲解
Must…do…? to.
Yes,…must.
No,…needn’t/don’t have
have to
只好,不得不(客观的必须,有时态和人称的变化)
don’t have to do
Do…have to do…?
Yes,…do.
No,…don’t.
ought to
What would she be doing there?
情态动词+have done的用法
could+have done:本可以做而实际上未能做。
You could have done better, but you didn’t try your best.
cannot+ have done:表示对现在或过去行为的否定推测。
③Had I been free,I would have visited you.
混合虚拟条件句
不同时间的虚拟:各遵守各的规则
①If he had listened to me, he would not be in trouble now.
②If he had told me yesterday,I should know what to do now.
need
need作为情态动词只有一种形式,只用于否定句和疑问句。
dare
dare作为情态动词用时有两种形式:dare和dared两个词形,除了可以用于否定句和疑问句外,还可以用于条件从句或表示怀疑的句子中。
If he dare come,I will kick him out. I don’t know whether he
for I worked to use it.
情态动词和虚拟语气
谓语动词(情态动词、虚拟语气)要点一情态动词的基本用法【温馨提示】can有时也用于肯定句,表示理论上的可能性或一时的情况。
常译为“有时会”。
2.may,might【温馨提示】may表示请求许可时,其否定回答一般用mustn’t。
may not意为“可能不”,而can’t意为“不可能”。
3.will,would【温馨提示】would表示过去的习惯时仅指动作,而且不与现在作对比;used to表示过去的习惯动作或状态,而且与现在作对比,说明现在这种动作或状态已经不存在。
4.shall,should,ought to5.must,have to【温馨提示】 (1)在回答must 的问句时,否定回答通常用needn ’t 或don ’t have to 。
(2) mustn ’t 表示“禁止;不许”;而don ’t have to表示“不必”。
(3) must 只有一种形式,而have to 有人称、时态的变化。
7.dare 的用法【温馨提示】 (1)dare 用作情态动词有dare,dared 两种形式。
(2)dare 用作实义动词,后接不定式,不定式符号to 可省去,但dare 以动词-ing 形式出现时,不定式符号to 不能省略。
要点二 “情态动词+have done ”的用法1.must have done表示对过去已发生的事情进行肯定的推断,只用于肯定句中,意为“一定,必定”,其否定形式为:can’t/cannot have done。
It must have rained last night,for the road was quite wet.昨晚肯定下雨了,因为路面十分潮湿。
I saw Mr Wang just now.He can’t have gone abroad.刚刚我还看见王先生了,他不可能已经出国了。
2.could have done意为“本来可以……,本来能够……”,表示虚拟语气。
虚拟语气与情态动词语法讲解
Would you mind turning the light on? Could you come a little earlier next time?
(3)提出建议或劝告 You had better leave the matter to me. You’d better not go shopping everyday. Perhaps you could get better results this way.
虚 拟条件句
动词过去式 或 should + 动词原形 或 were to + 动词原形
主
句
should / would / could / might + 动词原形
If it were to rain tomorrow, we should not go out. If they should farm the land themselves, they would get more grain.
B)在目的状语从句中总是有一个情态动词 The teacher spoke slowly in order that the students could hear clearly.
C)以 lest(唯恐) for fear that(以免) 和 in case(万一) 引 起的条件从句中动词用 should + 动词原形 He took his raincoat with him lest it should rain. He put his coat over the child for fear that (lest) he should catch cold. Here’s some money in case you should need it.
虚拟语气与情态动词的区别及用法解析
虚拟语气与情态动词的区别及用法解析虚拟语气和情态动词是语法中两个不同的概念,但在一些语法规则和用法上有一些相似之处。
虚拟语气是一种用来表示假设、愿望、建议、要求等非现实情况的语气,它并不是真实存在的,而是对虚构的事件或状态进行描述。
而情态动词则是一类用于表示说话人的态度、推测、能力、许可等情态意义的动词。
一、虚拟语气的用法1. 假设虚拟语气经常用于表示虚拟的假设情况,即与事实相反或不可能实现的情况。
常见的虚拟语气形式包括“如果…(过去式)”,“要是…(过去式)”等。
例如:- If I were a bird, I would fly freely in the sky.如果我是一只鸟,我就可以在天空中自由飞翔。
2. 愿望虚拟语气还可以用于表示愿望,即对现实情况的一种虚构或想象。
常见的虚拟语气形式包括“希望…(过去式)”,“但愿…(过去式)”等。
例如:- I wish I had studied harder last night.我希望昨晚学习更努力一些。
3. 建议、要求虚拟语气还可以用于表示建议、要求等情况。
常见的虚拟语气形式包括“(要求、建议)+过去式”。
例如:- The doctor suggested that I take some rest.医生建议我休息一下。
二、情态动词的用法1. 表示能力、推测情态动词可以用来表示说话人的能力或对某种情况的判断。
常见的情态动词有can、could、may、might等。
例如:- She can swim very well.她游泳技术非常好。
2. 表示许可、允许情态动词还可以表示许可或允许的意思。
常见的情态动词有can、may等。
例如:- Can I borrow your pen?我能借用你的笔吗?3. 表示义务、应该情态动词也可以表示说话人对某种行为或义务的责任或要求。
常见的情态动词有should、ought to等。
例如:- You should apologize to him for your mistake.你应该为你的错误向他道歉。
虚拟语气与情态动词
虚拟语气与情态动词虚拟语气表示说话人的愿望、假设、猜测或建议,而不表示客观存在的事实。
虚拟语气通过谓语动词的特殊形式来表示,下面对虚拟语气在各种句式中的用法分别介绍。
虚拟语气用于条件状语从句。
表示与现在事实相反的假设时,条件状语从句中的谓语动词用“过去式(be的过去式用were)”,而主句中的谓语动词用“would(should, could, might)+动词原形。
”例如:If I were you, I should studay English.If he had time, he would attend the meeting.表示与过去的事实相反的假设时,条件状语从句的谓语动词用“had +过去分词”,主句中的谓语动词用“would(should, could, might)+have +过去分词”。
例如:If you had taken my advice, you wouldn’t have failed in the examination.表示与将来事实相反的假设时,条件从句和主句所用的谓语动词怀“表示与现在事实相反的假设”的谓语动词相同,或者条件从句中用“were to(should)+动词原形”。
例如:If you come tomorrow, we would have the meeting.If it were to rain tomorrow, the meeting would be put off.当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时,动词的形式要根据它所表示的时间来调整。
例如:If you had worked hard, you would be very tired.(从句说的是过去,主句指的是现在.)5.以上句型可以转换成下列形式:1)省略if,用“were, have, should +主语”. 例如:Were I in school again, I would work harder.Had you been here earlier, you would have seen him.Should there be a meeting tomorrow, I would come.但在虚拟条件状语从句中,省略连词的倒装形式的句首不能用动词的缩略形式,如我们可以说:Were it not for the expense, I would go to Italy.但不能说Weren’t it for the expense, I would go to Italy.2)用介词短语代替条件状语从句.例如:Without air, there would be on living things.But for your help, I couldn’t have done it.3)用其了方式表示.例如:It would produce had results to do that.= If you have done that, it would produce bad results.(二)虚拟语气用于宾语从句“wish +宾语从句”表示不能实现的愿望,汉语可译为“可惜……”. “……就好了”, “悔不该……”, “但愿……”等.表示现在不能实现的愿望,从句的谓语动词用过去式;表示将来不能实现的愿望用“would(could) +动词原形”;表示过去不能实现的愿望时用“had +过去分词”或“(could)would +have +过去分词”.例如:I wish it were spring all the year round.I wish you could go with us.We wish we had arrived there two hours earlier.虚拟语气在动词arrange, command, demand, desire, insist, order, propose, request, require, suggest,等后面的宾主从句中用“(should)+动词原形”.例如:We suggested that we (should) have a meeting.We insisted that they (should) go with us.The doctor ordered that she (should) stay in bed for a few days.He demanded that we (should) start right away.注意:insist作“力言”, “强调”解时,宾语从句不用虚拟语气,只有当insist作“坚持(认为)”, “坚持(应该)”解时宾语从句才用虚拟语气.例如:Mike insisted that he had never stolen anything.(三)虚拟语气用于表语从句、同位语从句作advice, idea, order, demand, plan, proposal, suggestion, request等名词的表语从句和同位语从句,其谓语动词要用虚拟语气的结构“(should)+动词原形”.例如:We all agreed to his suggestion that we (should) go to Beijing forsightseeing.My idea is that we (should) exercises first.(四)虚拟语气在as if(as though),even if( even though)等引导的表语从句或状语从句中的应用.如果从句表示的动作发生在过去,用过去完成时,指现在状况,则用过去时,指将来则用过去将来时.例如:He looked as if he were an artist.He speaks English so fluently as if he had studied English in England.Even if he were here,he could not solve the problem.(五)虚拟语气用于主语从句.在主语从句中,谓语动词的虚拟语气结构用“should 十动词原形”的结构,表示惊奇、不相信、惋惜、理应如此等.例如:It is necessary( important,natural,strange,etc) that …we should cleanthe room every day.It was a pity ( a shame,no wonder,etc) that you should be so careless.It will be desired( suggested,decided,ordered,requested,proposed,etc)that she should finish her homework this afternoon.在上述三种主语从句中,should意为“应该”,“竟然”,可以省去,但不可换用would.主句所用动词的时态不限.注意:这种从句表示的是事实.如果说话人对这种事实表现出惊奇的情感,就可用虚拟语气.反之,如果不表示惊奇等情感.That从句也可用陈述语气,例如:It is a strange that he did not come yesterday.It is a pity that you can’t swim.(六)虚拟语气用于定语从句这种从句常用在It is( high) time( that)…句型中,定语从句的谓语动词用过去式,或should十动词原形( should不能省略,be用were)来表示,意为“(现在)该……”。
初三语法讲解情态动词倒装和虚拟语气的用法详解
初三语法讲解情态动词倒装和虚拟语气的用法详解情态动词和倒装结构情态动词是一类特殊的助动词,用于表示说话人的意愿、能力、推测等情态。
常见的情态动词包括can,could,may,might,shall,should,will,would,must等。
在某些情况下,情态动词与主语之间可以发生倒装,以强调主语、表示感叹或表示紧迫性。
1. 情态动词加入倒装情态动词的倒装结构通常由情态动词+主语构成,主谓倒装。
这种结构常用于以下几个情境:a) 表示强调和感叹例如:Never have I seen such a beautiful sunset. 我从未见过这样美丽的日落。
How brave he is! 他真勇敢!b) 表示建议或命令例如:May you have a pleasant journey! 祝你旅途愉快!Should you need any assistance, please contact us. 如需帮助,请联系我们。
c) 表示条件例如:Were he here, he would help us. 如果他在这里,他会帮助我们的。
2. 情态动词与not一起的倒装当情态动词与not连用时,可以将not置于句首,构成动词的倒装结构。
这种结构常用于祈使句或表示强调的句子中。
常见的结构有:a) Shall not例如:Shall you not tell her the truth? 你难道不应该告诉她实情吗?b) Will not例如:Will you not accompany me to the party? 你难道不会陪我去参加聚会吗?c) Can not例如:Can you not see the sign? 你难道没有看到标志吗?虚拟语气的用法虚拟语气是表示与事实相反、假设或愿望等非真实情况的一种语气。
在英语中,虚拟语气主要通过动词的形态和从句结构来表达。
1. 虚拟语气的形态a) 过去时当表示与现在或将来相反的非真实情况时,常用虚拟语气的过去时态。
高考英语二轮复习情态动词和虚拟语气考点讲解含解析
情态动词和虚拟语气第一部分、情态动词一、can/could与be able to1.can/could用来表示“一般能力”;be able to有多种时态,且用来表示在特定条件下的“具体能力”.如:My grandma is over seventy,but she can still read without glasses.They will be able to tell you the news soon.He was able to flee Europe before the war broke out.2.表示允许可用can或could,与may/might意义接近.could可用于现在时,只是语气更加委婉、客气,回答时则一般要用can而不用could.—Could I have the television on?—Yes,you can./No,you can't.二、may与might1.表示允许,意为“可以,许可”,用法基本上同can与could.如:May I use your bicycle?2.表示可能性,意为“也许,可能”.如:According to the weather forecast, it may rain tomorrow.3.may可以放在句首,表示祝愿.如:May good luck be yours!三、must与have to1.must用来表示说话人的主观看法;have to表示客观的需要,强调外界压力,不得已而为之.如: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)My brother was ill, so I had to call the doctor in the middle of the night.我弟弟生病了,我只得半夜里把医生请来.(客观上需要做这件事)2.表示“不必”,须用don't have to或needn't.must的否定式表示“禁止,绝对不可”.如:You don't have to tell him about it.你不必告诉他那件事.You mustn't tell him about it.你绝不能告诉他那件事.—Must we do it now?我们必须现在做吗?—No, you needn't.不,你们不必.四、shall1.用于第一、第三人称的疑问句中,用来征求对方的意见或请求指示.如:What shall he do next?他下一步干什么呢?2.用于第二、第三人称的陈述句中,表示说话人的意愿,有“命令、警告、允诺、威胁、强制”等意思.如:He shall stay in bed.他必须躺在床上.You shall have it back next week.下周一定还你.He says he won't go, but I say he shall.他说他不去,但我说他必须去.五、will与would1.will用于各种人称,表示“意志、意愿”或“决心”等.如:If you will keep your watch half an hour slow, it is hardly surprising that you are late for your appointments.如果你想要让你的表慢半个小时,你约会时迟到就不足为怪了.2.will表示习惯性的动作,有“总是,惯于”的含义.如:An Englishman will usually show you the way in the street.英国人通常是会在街上给你指路的.3.would可表示过去反复发生的动作.如:On Sundays he would get up early and go fishing.星期天他总是早起去钓鱼.六、should与ought to1.should表示“建议”或“劝告”,有“应该”之意.如:You should learn from each other.2.ought to表示根据某种义务或必要“应当”做某事.如:Everyone ought to obey the traffic regulations.3.should和ought to也可用来表示推测,意为“想必会……”.如:—When can I come for the photos? I need them tomorrow afternoon.—They should be ready by 1200.七、情态动词表示推测1.can用于肯定句中表示客观的可能性,意为“有时会”;用于疑问句中可以表示推测,意为“可能”,有时表示一种惊讶的语气;用于否定句中也可以表示推测,can't意为“不可能”,语气很强烈.It is usually warm in my hometown in March, but it can be rather cold sometimes.我的家乡在三月份通常很暖和,但有时候也会相当冷.Mr. Bush is on time for everything. How can it be that he was late for the meeting?布什先生做什么事情都很准时,他怎么可能开会迟到呢?—Let's visit Tom together, Stephen.—There's no need to do so. He can't be at home, because I saw him board the flight to Beijing this morning.——Stephen,咱们一起拜访汤姆吧.——没必要这样做.他一定不在家,因为今天早晨我看见他登上了飞往北京的航班.2.may/might用于肯定句中可以用来表示不十分肯定的推测,意为“有可能”;用于否定句中也可以表示推测,may not意为“可能不”,表示一种不太确定的语气.The traffic is heavy these days. I might arrive a bit late, so could you save me a place?这些天交通很繁忙,我可能会来晚一点,请你帮我保留个位置好吗?3.must表示推测时只能用于肯定句中,意为“一定,必定”,表示十分肯定的语气(在疑问句中或否定句中要用can/could).—It's the office! So you must know eating is not allowed here.—Oh, sorry.——这是办公室!所以你一定知道这里不许吃东西.——噢,对不起.4.should用来表示推测时意为“应该”,即含有“按道理来说应当如此”的意思.There shouldn't be any difficulty about passing the road test since you have practiced a lotin the driving school.因为你在驾校训练了这么多,通过路考应该没什么困难.八、“情态动词+have done”结构1.should/ought to+have done,表示“过去本应该做而(实际)没有做的事情”,含有责备或遗憾的语气,意为“本应该……”.其否定形式为“should not/ought not to have+done”,表示某种行为本不该发生但实际上发生了.I shouldn't have watched that movie—it'll give me horrible dreams.我本不应该看那部电影——它会令我做噩梦.You ought to have come to the party yesterday, but why didn't you come?昨天你本来应该参加聚会的,可是你为什么不来?2.must+have done,用于肯定句,表示“过去一定做过某事”,表示一种很有把握的推测.注意,对过去发生的情况的否定推测常用“can't/couldn't+have done”表示.—Ye Shiwen won two gold medals in London Olympic Games.—She must have gone through tough training.——叶诗文在伦敦奥运会获得了两枚金牌.——她肯定受到严格的训练.—Do you know where David is? I couldn't find him anywhere.—Well. He can't have gone far—his coat's still here.——你知道大卫在哪里吗?我到处找不到他.——大卫的上衣还在这里,因此他肯定没走远.3.needn't+have done,表示“过去没有必要做某事,但实际上做了某事”.Mark needn't have hurried. After driving at top speed, he arrived half an hour early.马克本没必要那么匆忙.他以最快速度开车,结果早到了半个小时.4.may/might+have done,表示对过去情况的一种不太有把握的可能性的推测,表示“可能已做了某事……”,否定句表示“可能还没有……”.Sorry, I'm late. I might have turned off the alarm clock and gone back to sleep again.对不起,我迟到了.我可能把闹钟关掉后又睡着了.5.could+have done表示“过去本来可以做某事,但实际上没有做”;can/could+have done表示“过去可能做了某件事”.I could have saved the poor rabbit, but I didn't have the right drugs with me at that moment.我本来可以拯救那只可怜的兔子的,可是我当时没有合适的药品.第二部分、虚拟语气一、虚拟语气在虚拟条件句中的用法1.在具体运用中,条件从句中有时可省略if而采用倒装结构.如:Had it not been for your help, we wouldn't have achieved so much.2.介词without/but for、连词but、副词otherwise常用来表示某种假设条件.如:I wouldn't have made such rapid progress without your help.3.有时候从句动作和主句动作发生的时间不一致,这时谓语动词的形式要根据各自的时间来调整.如:If the weather had been more favourable, the crops would be growing still better.二、“should+动词原形”表示的虚拟语气这一类型常见词有“一坚持(insist)、二命令(order, command)、三建议(advise, suggest, propose)、四要求(request, require, demand, desire)”.以上词及其派生名词所接的名词性从句都使用“(should +)动词原形”的虚拟语气.①Jane's pale face suggested that she was ill, and her mother suggested that she(should) havea medical examination.简苍白的脸色表明她病了,她母亲建议她去检查身体.②She insisted that the man had stolen her car and that he(should) be sent to prison.她坚持说那个男人偷了她的车,并坚决要求他坐牢.三、特殊句式中的虚拟语气If only/It's (high) time (that)...wish/would rather/as if等固定句式要求用相应的虚拟语气表达形式.①I wish I could fly.真希望我能飞.②I would rather you came tomorrow.我宁愿你明天来.③If only I had taken your advice!要是听从了你的建议该多好啊!高频考点一、考查情态动词例1.(2018·北京卷)In today’s information age, the loss of data _________ cause serious problems for a company.A. needB. shouldC. canD. must【答案】C【解析】考查情态动词.句意:在今天的信息时代,数据的丢失有时会对一个公司造成严重的问题.数据丢失造成严重问题是客观上会发生的情况,即“客观可能性”,故该空应用情态动词can.C选项正确.其余情态动词均没有该用法.need需要;should应该,竟然;must必须,肯定.【变式探究】—Can’t you stay a little longer?—It’s getting late. I reall y _____go now, My daughter is home alone.A .mayB .canC . mustD .dare【答案】C【解析】句意:——你不能再多待会儿吗?——很晚了,我必须得走了.我女儿一个人在家.A. may可能,可以,也许;B. can能,会;C. must必须,必然要,必定会;D. dare敢,胆敢.结合句意,故选C.【变式探究】________ I have a word with you? It won’t take long.A. CanB. MustC. ShallD. Should【答案】A【解析】本题考察的是情态动词基本意义辨析.Can能够,可能;must必须,一定;非得;shall将要;should应该;句意:我可以和你谈谈吗?不会花很多时间的.根据句意可知本题使用can I…?表示询问对方是否允许.如:Can I use your dictionary?我可以使用你的字典吗?故A正确.高频考点二、考查情态动词的用法例2. (2018·天津卷) I can't find my purse. I___________ it in the supermarket yesterday, but I'm not sure.A. should leaveB. must have leftC. might leaveD. could have left【答案】D【解析】考查情态动词表推测.句意:我不能找到我的钱包了,昨天我有可能把它落到超市了,但我不确定.根据句中时间状语yesterday可知,是对过去事情的推测,故用情态动词+ have done,再根据后句but I’m not sure.可知,此推测为不能肯定的推测,故用情态动词could,表示“可能”.故选D.【变式探究】(2017•天津)My room is a mess, but I __________clean it before I go out tonight.I can do it in the morning.A. daren’tB. shouldn’tC. needn’tD. mustn’t【答案】C【解析】句意:我的房间很乱,但是在今晚我出去之前不需要打扫,我可以明天早晨再打扫.A.不敢;B.不应该;C不需要;D.不许.根据句意,故选C.【变式探究】Why didn't you tell me about your trouble last week?If you ________(tell)me,I could have helped.【答案】had told【解析】句意:上个星期你为什么不告诉我你的麻烦事?如果你告诉我了,我就能帮你.根据句意和相关信息判断,条件句表示与过去事实相反的假设,此时从句用过去完成时,主句谓语用“情态动词+have done”形式.【变式探究】I ______ have worried before I came to the new school, for my classmates here are very friendly to me.A. mightn’tB. mustn’tC. needn’tD. couldn’t【答案】C【解析】句意:我来新学校之前本没有必要担心,因为在这里我的同学对我非常友好.needn’t have done本没有必要做某事,表示实际上已经做了某事.根据句意可知选C.高频考点三、考查虚拟语气例3.(2019·天津卷)The workers were not better organized, otherwise they ________ the task in half the time.A.accomplished B.had accomplishedC.would accomplish D.would have accomplished【答案】D【解析】考查虚拟语气.句意:工人们没有被组织好,否则的话他们会用那一半的时间完成任务的.此处otherwise表达了一种含蓄虚拟;otherwise前的内容所述的是过去的事实,相当于if引导的条件状语从句“If the workers had been better organized”,因此后半部分应用“主语+would have done sth.”的结构.故选D.【举一反三】【2018·江苏】It’s strange that he _______have taken the books without the owner’s permission.A. wouldB. shouldC. couldD. might【答案】B【解析】考查虚拟语气.句意:真奇怪,他竟然没有主人的允许就拿走了这些书.在句型”It is important/necessary/strange/impossible/natural that...”中,其中由that引导的主语从句通常用“should+动词原形”这样的虚拟语气,其中的should可以省略.故选B.【变式探究】(2017·北京)If the new safety system _______ to use, the accident would never have happened.A. had been putB. were putC. should be putD. would be put【答案】A【解析】句意:如果这个新的安全系统被投入使用过的话,这个事故就不会发生了.根据主句确定是对过去情况的虚拟,所以从句谓语用had done形式,此外根据句意可知是被动,用被动语态,故A项是正确的.【变式探究】________(have)the governments and scientists not worked together,AIDSrelated deaths would not have fallen since their highest in 2005.【答案】Had【解析】句意:如果政府和科学家不共同努力,与艾滋病相关的死亡就不会从2005年的最高点下降.这是一个省略了从属连词if的虚拟语气句,使用了倒装句式.根据主句的would not have fallen可知,这里是表示过去的虚拟语气,所以用had.【变式探究】Without his wartime experiences, Hemingway____ his famous novel A Farewell to Arms.A.didn’t writeB. hadn’t writtenC. wouldn’t w riteD. wouldn’t have written【答案】D【解析】句意:没有他战时的经验,海明威就不可能写出著名的小说永别了武器.根据without his wartime experience没有战时的经历,可知表示对于过去的否定猜测,故主句用would have done,因此选D 项.1.(2019·天津卷)The workers were not better organized, otherwise they ________ the task in half the time.A.accomplished B.had accomplishedC.would accomplish D.would have accomplished【答案】D【解析】考查虚拟语气.句意:工人们没有被组织好,否则的话他们会用那一半的时间完成任务的.此处otherwise表达了一种含蓄虚拟;otherwise前的内容所述的是过去的事实,相当于if引导的条件状语从句“If the workers had been better organized”,因此后半部分应用“主语+would have done sth.”的结构.故选D.2.(2019·江苏卷)What a pity! You missed the sightseeing, or we ________ a good time together.A.had B.will haveC.would have had D.had had【答案】C【解析】考查虚拟语气.句意:多么遗憾!你错过了这次游览.否则,我们就可以一起度过一段愉快的时光.根据关键词or可知,这里表示与过去的事实相反,谓语动词应用would/could/should/might+have done.1.【2018·江苏】 There is a good social life in the village, and I wish I _______ a second chance to become more involved.A. hadB. will haveC. would have hadD. have had【答案】A【解析】考查虚拟语气.句意:在这个村里有很好的社交生活,并且我希望我再有机会去更多的参与.本题考查wish引导的宾语从句,表示与现在事实相反的愿望,所以从句用一般过去时.故选A.2.【2018·江苏】It’s strange that he _______have taken the books without the owner’s permission.A. wouldB. shouldC. couldD. might【答案】B【解析】考查虚拟语气.句意:真奇怪,他竟然没有主人的允许就拿走了这些书.在句型”It isimport ant/necessary/strange/impossible/natural that...”中,其中由that引导的主语从句通常用“should+动词原形”这样的虚拟语气,其中的should可以省略.故选B.3.(2018·天津卷) I can't find my purse. I___________ it in the supermarket yesterday, but I'm not sure.A. should leaveB. must have leftC. might leaveD. could have left【答案】D【解析】考查情态动词表推测.句意:我不能找到我的钱包了,昨天我有可能把它落到超市了,但我不确定.根据句中时间状语yesterday可知,是对过去事情的推测,故用情态动词+ have done,再根据后句but I’m not sure.可知,此推测为不能肯定的推测,故用情态动词could,表示“可能”.故选D.4.(2018·北京卷)In today’s information age, the loss of data _________ cause serious problems for a company.A. needB. shouldC. canD. must【答案】C【解析】考查情态动词.句意:在今天的信息时代,数据的丢失有时会对一个公司造成严重的问题.数据丢失造成严重问题是客观上会发生的情况,即“客观可能性”,故该空应用情态动词can.C选项正确.其余情态动词均没有该用法.need需要;should应该,竟然;must必须,肯定.5.(2018·北京卷)They might have found a better hotel if they _________ a few more kilometers.A. droveB. would driveC. were to driveD. had driven【答案】D【解析】考查虚拟语气.句意:如果他们多开几公里的话,他们也许会找到一个更好的旅馆.由“they might have found a better hotel”可知,该句是表示对过去的虚拟.if ____ a few more kilometers是条件句部分,表示对过去的虚拟,条件句部分要用过去完成时态,故D选项正确.1.(2017·北京)Samuel, the tallest boy in our class, ______ easily reach the books on the top shelf.A. mustB. shouldC. canD. need【答案】C【解析】A. must 必须 B. should 应该 C. can 能 D. need 需要.句意:Samuel,我班最高的男生,能很轻松地够着书架顶上的书,此处需要一个表示能力的词,故用can,答案为C.2.(2017•天津)My room is a mess, but I __________clean it before I go out tonight. I can do it in the morning.A. daren’tB. shouldn’tC. needn’tD. mustn’t【答案】C【解析】句意:我的房间很乱,但是在今晚我出去之前不需要打扫,我可以明天早晨再打扫.A.不敢;B.不应该;C不需要;D.不许.根据句意,故选C.3.(2017•江苏) _______ not for the support of the teachers, the student could not overcome her difficulty.A. It wereB. Were itC. It wasD. Was it【答案】B【解析】考查虚拟语气和倒装.虚拟语气中,be动词统一用were;虚拟语气的省略形式主要是把if省略,同时把were/should/had提前,即Were /Should/ Had I...,故选B.句意:要不是老师们的支持,该生是无法克服她自己的困难的.4.(2017·江苏卷) ____________ not for the support of the teachers, the student could not overcome her difficulty.A. It wereB. Were itC. It wasD. Was it【答案】B【解析】考查虚拟语气的省略.虚拟语气中,be动词统一用were;虚拟语气的省略形式主要是把if省略,同时把were/should/had提前,即Were /Should/ Had I...,故选B.5.(2017•江苏) _______ not for the support of the teachers, the student could not overcomeher difficulty.A. It wereB. Were itC. It wasD. Was it【答案】B【解析】考查虚拟语气和倒装.虚拟语气中,be动词统一用were;虚拟语气的省略形式主要是把if省略,同时把were/should/had提前,即Were /Should/ Had I...,故选B.句意:要不是老师们的支持,该生是无法克服她自己的困难的.6.(2017·北京)If the new safety system _______ to use, the accident would never have happened.A. had been putB. were putC. should be putD. would be put【答案】A【解析】句意:如果这个新的安全系统被投入使用过的话,这个事故就不会发生了.根据主句确定是对过去情况的虚拟,所以从句谓语用had done形式,此外根据句意可知是被动,用被动语态,故A项是正确的.1.(2016·浙江,15)________(have)the governments and scientists not worked together,AIDSrelated deaths would not have fallen since their highest in 2005.【答案】Had【解析】句意:如果政府和科学家不共同努力,与艾滋病相关的死亡就不会从2005年的最高点下降.这是一个省略了从属连词if的虚拟语气句,使用了倒装句式.根据主句的would not have fallen可知,这里是表示过去的虚拟语气,所以用had.2.(2016·浙江,17)George can't ________(go)too far.His coffee is still warm.【答案】have gone【解析】句意:乔治不可能走得太远了.他的咖啡仍然是温的.can't have done是对过去的否定推测.3.(2016·北京,34)Why didn't you tell me about your trouble last week?If you ________(tell)me,I could have helped.【答案】had told【解析】句意:上个星期你为什么不告诉我你的麻烦事?如果你告诉我了,我就能帮你.根据句意和相关信息判断,条件句表示与过去事实相反的假设,此时从句用过去完成时,主句谓语用“情态动词+have done”形式.。
情态动词与虚拟语气
情态动词与虚拟语气【语法要点】情态动词所谓情态动词是指它含有一定的含义,可以表达某种感情和说话的语气,但是它不可以单独使用作谓语动词。
学习情态动词主要学习英语国家的语言习惯和表达法,特别是在口语中不要过分追求原理,更不要不根据说话场合而进行推理,编造出一些语法结构正确的中文式英语。
一、情态动词的类型1.只作情态动词的有:must、can、could、may、might、ought to2.既可作情态动词又可作实义动词的有:need、dare3.既可作情态动词又可作助动词的有:shall、should、will、would二、情态动词的特征1.表示说话人的情感态度,不能单独作谓语,与行为动词或连系动词一起作谓语。
2.情态动词没有人称和数的变化,后接动词原形。
3.具有助动词的特征:可用来构成否定句、疑问句或简短答语。
三、情态动词的用法1.表示能力(1)表示现在的能力,用can或be able to。
表示一般的能力时多用can,表示“经过努力成功的做成某事”用be able to。
(2)表示过去的能力,用could或was/were be able to。
区别同上。
(3)表示将来的能力,用will be able to。
2.表示推测、可能性(1)can用在肯定句中表示客观的可能性,而不表示具体事情实际发生的可能性。
例如:Accidents can happy on such rainy days.(2)表示具体事情实际发生的可能性的情态动词,其表示可能性的层次如下表:情态动词肯定式否定式疑问式must 必定、必然、一定will 很可能、大概不会、不该会……吗?would 可能性较will小不会、不该(较won’t弱)会……吗?(较will弱)should 应该会、理应(表示合乎理想的情况或结果)ought to 与should同义can 一定不会、不可能(否定推测)有可能吗?could 可疑的可能不可能(与can’t同义)有可能吗?(较can弱)may 或许、可能、说不定可能不might 或许、可能(较may弱)可能不(较may not弱)注意→(1)may,must常用于肯定句,一般不用于否定句和疑问句。
高考英语二轮 情态动词和虚拟语气2课件
5.(2011·四川)The police still haven’t found the lost child, but they’re doing all they ________.
A.can B.may C.must D.should 解析 考查情态动词的用法。句意为“警方依然没有找到失 踪的孩子,但他们现在正在做他们所能做的一切。”can可以, 能够;may可能,许可;must必须;should应该。根据句意, 选A。 答案 A
2.(2010·北京)—Good morning. I’ve got an appointment with Miss Smith in the Personnel Department. —Ah,good morning. You________be Mrs. Peters. A.might B.must C.would D.can 解析 此题考查情态动词。第一句说明和史密斯女士有约定, 所以秘书判断一定是 „„ 。 must 在此表示推测,意为 “ 一 定”,符合语境。 答案 B
1.(2011·北京)—I don’t really like James. Why did you invite him? —Don’t worry. He________come. He said he wasn’t certain what his plans were. A. must not B. need not C. would not D. might not 解析 考查情态动词的用法。句意为 “—— 我真不喜欢 James。 你为何请了他?——别担心。他可能来不了。他说他的计划还 没安排好。”题干中的he wasn’t certain说明他可能不来,可 能来,因此使用不完全否定might not。选D。 答案 D
情态动词和虚拟语气讲解
情态动词和虚拟语气一、命题趋势高考中,短文改错和语法填空主要以情态动词误用,情态动词后实意动词的形式错误或时态错误等考察对情态动词和虚拟语气的理解和运用。
二、考纲内容1.熟悉情态动词常见的意义、作用、用法及变化形式;了解情态动词与进行时、完成时连用时所表达的意义。
2.熟悉非真实条件虚拟语气的形式、意义;了解虚拟条件的省略及混合虚拟条件语气;了解名词性从句、方式状语从句中的虚拟语气情况。
三、情态动词(一)情态动词1.情态动词的概述情态动词主要用以表明说话者对某一行为的态度和观点,主要包括揣测、判断、需要、可能、各种意愿等。
2.情态动词的特征(1)有一定的词义,但不能单独作谓语。
他们要和动词原形一起构成谓语。
(2)适用于主语的各种人称和数(have to 例外,当其主语是第三人称单数时用has to。
)(3)后接动词原形。
(二)情态动词的用法1.can, could(1)表示能力:can表示现在的能力,could表示过去的能力。
例:Although he is only four, he can play the piano.(2)表示请求:could 不表示过去,只表示客气、委婉的口气,但回答时必须用can.例:--Could I borrow your bicycle?--Yes, you can/ No, you can’t.(3)表示可能行:一般用在否定句和疑问句中,could也可用于肯定句。
例:That can not be Mary, for she is in hospital.注意:can有时也用于肯定句,表示理论上的可能性或一时的情况,常译为“有时会”。
例: Mother can be very forgetful sometimes.辨析: can与be able to(1)表示能力时,can与be able to意义相同,但是can仅用于一般现在时及一般过去时,be able to可用于更多时态。
高中语法精要情态动词和虚拟语气
高中语法精要情态动词和虚拟语气高中语法精要:情态动词和虚拟语气在高中英语学习的过程中,语法是一个不可或缺的部分。
情态动词和虚拟语气是其中重要且常被混淆的概念。
本文将全面介绍情态动词和虚拟语气的用法及相关注意事项。
一、情态动词情态动词是用来表示说话人的情感、推测、能力等方面的动词。
常见的情态动词包括can、could、may、might、shall、should、will、would、must等。
1. 表示能力:Can和could用于表示某人具有能力做某事。
例如:- I can swim.(我会游泳。
)- He could speak French when he was young.(他年轻时会说法语。
)2. 表示推测:May、might和could可以用于表示推测或可能性。
例如:- It may rain later.(可能会下雨。
)- He might be busy.(他可能很忙。
)3. 表示许可:Can和may用于表示允许或许可。
例如:- Can I go to the bathroom?(我可以去洗手间吗?)- May I borrow your pen?(我可以借用你的笔吗?)4. 表示建议和意愿:Should和would常用于表示建议、意愿或假设情况。
例如:- You should eat more vegetables.(你应该多吃蔬菜。
)- I would like some tea, please.(我想要一些茶,谢谢。
)二、虚拟语气虚拟语气是用来表示非现实情况或假设情况的一种语气形式。
在高中英语中,虚拟语气主要包括与过去事实相反的虚拟语气、与现在事实相反的虚拟语气、与将来事实相反的虚拟语气以及情态动词的虚拟语气等。
1. 与过去事实相反的虚拟语气:与过去事实相反的虚拟语气常由"were"来表示,无论主语是单数还是复数,都使用"were"。
情态动词与虚拟语气知识点讲解
条件句
but for+名词表示虚拟条件
句子或主句中的谓语动词的形式视具体情况而定。这是考查考生应变能力的最佳试题。
---But for your timely warning,we ______
into great trouble.
---You know we’re friends.
A. would getB. must have got
need
need作为情态动词只有一种形式,只用于否定句和疑问句。
dare
dare作为情态动词用时有两种形式:dare和dared两个词形,除了可以用于否定句和疑问句外,还可以用于条件从句或表示怀疑的句子中。
If he dare come,I will kick him out. I don’t know whether he
used/usen’t to do
didn’t use to do
Used…to do…?
Did…use to do…?
Yes,…used.
No,…use(d)n’t.
Yes,…did.
No,…didn’t.
II.情态动词的重点知识
表示“能力、许可”的can和may
would可表示过去反复发生的动作或某种倾向。
During the vacation he would visit me every week
The wound would not heal.(伤口老是不能愈合)
would表示估计或猜想。
It would be about ten when he left home.
A.needn’tB.can’tC.should D.may
在疑问句只能用can,不能用may和must。
第九节情态动词和虚拟语气讲义-高三英语一轮复习
第九节情态动词和虚拟语气〔真题演练〕1. (经典高考)I can’t find my purse. I could (leave)it in the supermarket yesterday, but I’m not sure.2. (经典高考)Truly elegant chopsticks might (make)of gold and silver with Chinese characters.3. (经典高考)What a pity! You missed the sightseeing, or we(have) a good time together.4. (经典高考)If we (catch)the flight yesterday, we would be enjoying our holiday on the beach now.〔必备知识〕考点一情态动词1.情态动词的基本用法情态动词用法例句can/could表示“能力”,意为“能,会”Samuel, the tallest boy in our class,can easily reach the books on the top shelf. Samuel是我们班最高的男孩,他能轻易地拿到书架顶层的书。
表示推测,意为“可能”,往往用于否定句或疑问句中。
can比could语气强That can’t be Mary—she is in London now.那不可能是玛丽——她现在在伦敦。
表示客观可能性,意为“有时候会”,多用于肯定句Credit cards provide us with lots of convenience, but sometimes they can lead to problems.信用卡给我们提供了许多方便,但有时候会带来一些问题。
表示礼貌地请求,意为“能,可以”。
在疑问句中could可代替can, 语气更委婉Can you tell us your recipe for happiness and a long life?你能告诉我们你幸福和长寿的秘诀吗?固定句式:can’t...too/enough“无论多么……也不过分”“越……越好”I can’t thank you too much for all your help to my son while we were away from home.我非常感谢你在我们不在家时对我儿子的帮助。
情态动词与虚拟语气讲解
情态动词与虚拟语气一.情态动词1. 情态动词的基本用法1)must意为“必须,一定,得”用以表示说话人认为或某种客观情况要求某人“必须......”,表示的是命令性的语气。
You must hand in your composition today.**注意:回答must引起的一般疑问句,如果是否定意思,常用needn't。
如用mustn't 则表示“禁止”。
Cars mustn't park in front of the entrance.must表示“偏要,硬要”做某事。
2)can表示能力:表示客观(理论)上的可能性,用于肯定句中:Anybody can make mistakes.表示惊讶、怀疑、不相信,主要用于否定句、疑问句和感叹句Can the news be true?cannot but do sth.“不得不,只好”:I cannot but choose to go with them.cannot/ can never...enough/too“再......也不为过”:You cannot be too careful to cross the road.can not help but do, can not help doing“不得不”“禁不住” I can't help but often think of my parents.3)may 表示可能,“或许,也许”:She may come to your birthday party tomorrow.表示允许、许可。
否定回答时,一般要用mustn't,表示“禁止,阻止”:可以用于祈使句,表示祝愿:May we never forget each other.may/ might as well do sth.“最好,满可以,倒不如”:It's too late. You might as well not go.4)need既可作情态动词,又可作实义动词。
高中英语2025届高考语法复习情态动词与虚拟语气知识讲解
高考英语语法复习情态动词与虚拟语气知识讲解一、情态动词(1)表示能力时,can只用于一般现在时,could仅用于一般过去时;而be able to则有更多的时态,如将来时、完成时等。
I haven’t been able to read that report yet.He will be able to skate as well as you.(2)Was/were able to表示能力时,侧重经过努力而成功做到某事;而could仅表示具备能力,不说明是否实施了能力。
He studied hard and was able to pass the exam.(3)用在其他动词,如might,may,would,want,hope等之后表示能力只能用be able to。
He might be able to fix your car.(1)must还可以表示质问或感情色彩,意为“偏要,偏偏”。
Why must it snow on Saturday?(2)should还可以表示惊奇、愤怒、失望等特殊情感,尤其用在以why,who,how等开头的疑问句中或某些感叹句中。
why should you be so late today?(1)must作“必须”讲的一般疑问句,其肯定回答用must,否定回答用needn’t或don’t have to。
-Must I pay now?-Yes, you must./No, you needn’t.(2)need还可以作实义动词,有人称和数的变化,后跟带to的不定式作宾语。
She needed to go out for a walk.(1)两者在表示过去的习惯动作或行为时常可通用。
When we were children, we would/used to go skating every winter.(2)Used to与would都不能与表示具体频率、次数的词及特定的时间状语或具体的一段时间连用。
高中英语真题-第九讲 情态动词和虚拟语气
高中英语真题:第九讲情态动词和虚拟语气一、情态动词考点透析1.can (could),be able to。
can只有现在式can和过去式could两种形式, be able to可用于现在式、过去式、将来时、完成时。
要表示“能够做某事”,可用can或be able to,但若要说过去的确运用了某种能力做成了某件事情,就只能用was/were able to,表将来具备的能力只能用will/shall be able to。
(1)If you study hard,you will be able to express freely in English in three months. (2)The fire spread through the hotel very quickly but everyone was able to get out.2.could是can的过去式,但是在很多情况下,特别是在口语中,它表示语气的委婉。
因此,用could提问时,不能用could 回答,而要用can或may。
would,might用于疑问句时也表委婉语气,回答时应该用will,may。
(1)-Could I borrow your dictionary?-Yes,of course you can.(2)-Could I call you by the first name?-Yes,you may.(3)-Would you be so kind as to explain the word?-Yes,I will.What is it?3.may/might,can/could都可表示可能,但may/might 不能用于问句,can/could用于否定句、疑问句、感叹句,表示惊异、怀疑,一般不用于肯定句。
如果用于肯定句,则表示偶尔发生某事的可能,或某人某物一时的特点。
(1)-Are you coming to Jeff's party?-I'm not sure.I might go to the concert instead.(2)-Where can Mr.Li be?-Sorry,I don't know.You can go to ask Mr.Zhang.He may help you.(3)Mr.Bush is on time for everything.How can it be that he was l ate for the opening ceremony?(4)We enjoy good weather in January,but sometimes it can be terribly cold.4.must表推测用于肯定句,其否定式要用can't。
情态动词与虚拟语气知识点
情态动词与虚拟语气一、情态动词1.Can/could①表示能力:能/可以/会(could为过去式)②表示请求:可以(一般用于疑问句,could表示更委婉)注:could提问时,回答不能用could例:Could I smoke here?Yes,you can/No,you can’t③表示推测:不可能can't/couldn't(只用在否定句)注:表示推测时也可以用在疑问句或肯定句,但是很少,常见的例句:Can/Could it be true?That can/could be......2.may/might①表示请求:可以(一般用于疑问句,might表示更委婉)注:May提问,否定回答mustn't/can't②表示推测:也许(might比may可能性小)3.Must①表示命令/警告:必须(否定为mustn't“禁止”)注:must提问,否定回答needn't/don't have to②表示推测:一定(否定为can't“不可能”)4.will/would①用于构成将来时②表示意愿:会5.Need①实义动词need to do/need doing②情态动词(一般只用在疑问句或否定句)6.had better最好(注意否定had better not)7.Dare 敢(习惯接不定式,不过to也可以省略)8.Should ①应该②竟然注:ought to=should 应该9.have to 不得不Have to表示客观影响,must强调主观意愿10.be able to=canbe able to有时态变化,可以与其他情态动词连用,can不可以;另外,be able to更强调历经磨难,通过努力得到成功二、情态动词+have done1.三个推测(对过去的推测)①must have done:一定做了...②may/might have done:也许做了...③can't have done:肯定没做...2.could have done:本来能够做...例:You could have made greater progress,but you didn't.3.should/ought to have done:本该做...(却没做)4.needn't have done:本不必做...(却做了)5.Would have done:本会做...(实际上没做到)三、虚拟语气1.if的非真实条件句中例:①If I were you,I would accept his advice②If it rained/should rain/were to rain tomorrow,I would stay at home③If you had studied hard before,you would have passed the exam△if从句中,were/had/should可以放在句首(部分倒装),此时if必须省略,且否定词not不能放在前面例:①If I hadn't seen him then,I wouldn't have been very happy→Had I not seen him then,I wouldn't have been very happy②If I were you,I would accept his advice→Were I you,I would accept his advice2.错综时间条件句谓语动词根据句子本身的时态自行变化例:If you had followed my advice just now,you would be better now3.含蓄虚拟语气在某些介词存在的句子中,如果出现非真实的情况,要使用虚拟语气,常见的介词有:with/without/but for/or/but/otherwise等规则:例:①I was ill that day,otherwise,I would have taken part in the meeting②Without electricity,human being life would be quite different today4.wish与if only例:①I wish he could visit us tomorrow②If only you had listened to our advice!5.would rather(宁愿)/would sooner(宁可)/would as soon(宁愿)例:①I’d rather you came here tomorrow②I’d rather you hadn't told me the truth6.as if/as though例:①He looks as if he were an artist②He talked about the accident as though he had seen it7.用于建议(advise/suggest/propose/recommend)、命令(order/command)、要求(demand/require/request/desire/ask)、坚持要求(insist)、催促(urge)的从句中。
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第九讲情态动词和虚拟语气情态动词的5个基本用法1.表能力(1)表示现在的能力: can, am/is/are able to(2)表示将来的能力: will be able to(3)表示过去的能力: could表示过去的能力,不表示是否成功地做了;was/were able to表示过去有能力做而且成功地做了I’m going to Europe on vacation together with John if I can find the money.如果我能找到足够的金钱,我将和约翰一起去欧洲度假。
2.表推测(1)肯定句: can表示客观上的可能,有时会; may/might/could表示可能; must表示一定; should/ought to表示应该/按说应该(2)否定句:can’t/couldn’t表示不可能; may not/might not表示可能不;shouldn’t/oughtn’t to表示应该不会(3)疑问句: can/could表示惊讶、怀疑、不相信的态度Credit cards provide us with lots of convenience, but they can lead to problems.信用卡给我们提供了许多方便,但有时也会带来一些问题。
3.表请求、建议、命令、允许、允诺、禁止、义务、责任(1)请求对方允许时用May/Can/Could I/we... ?(2)主动提出帮忙或提出建议时用Shall I/we... ?(3)提出请求、问题、看法时用Will/Would you... ? 或Shallhe/she/they... ?(4)should/ought to表示应该,shouldn’t/oughtn’t to表示不应该(5)may/can(可以)表示允许、许可(6)must(必须), mustn’t表示禁止(7)shall与第二、三人称连用,用于陈述句,表示命令、警告、允诺、威胁;当宣布法律、规定时也常用shallOne of our rules is that every student shall wear school uniform while at school. (规定)我们其中的一项规定是,学生在校期间穿校服。
4.表必要性(1)must do sth. 表示“必须做某事”(2)needn’t/don’t have to表示“不必”You needn’t get the machine repaired this week. I won’t need it until next month.这周你不必请人修理机器,到下个月我才用呢。
5.表意愿、决心will/would可与各种人称连用,表示主语的意志或决心。
will表示意愿时其否定形式为won’t, 通常用于有生命体,但有时也用于无生命体,这时把无生命体拟人化了。
—Why hasn’t the cook arrived yet today?——为什么今天厨师还没来?—She just will not come for such a low salary.——这么低的薪水她不愿意来了。
情态动词的6种特殊用法1.can/could的否定式与比较级连用表示最高级。
2.can/could的否定式与enough或too (much)连用表示“再……也不为过”。
3.must可表示“偏要,硬要” , 常用于疑问句或条件状语从句。
4.may/might as well表示“最好;不妨” 。
5.would可表示过去的习惯,与used to相比,前者常表示过去反复的动作,后者常表示过去的状态或习惯,现在已不复存在。
6.should有时表示说话人对某事感到意外、惊奇,意为“竟然会” 。
If you must go, at least wait until the storm is over.如果你偏要走,至少等到暴风雨结束。
When we worked in the same firm several years ago, we would often go to the cinema together.12年前我们在同一个公司上班时,我们常常一起去看电影。
“情态动词+have done” 的2类用法1.对过去发生的事情或状态进行推测must have done (过去)一定……;语气比较肯定;用于肯定句may (might) have done (过去)可能……;语气不确定;用于肯定句和否定句can (could) have done 用于否定句和疑问句,表示怀疑或不确定Since nobody gave him any help, he must have done the research on his own.既然没有人帮助他,他一定是独自做的研究。
(浙江高考)I couldn’t have enjoyed myself more—it was a perfect day.我从没有玩得这么开心过——这真是完美的一天。
2.表示“与过去事实相反”could have done 过去本可以做某事但实际上没做needn’t have done过去本不必做某事但实际上做了ought to/should have done 过去本应该做某事但实际上没做oughtn’t to/shouldn’t have done过去不应该做某事但实际上做了might have done 过去可能做某事但实际上没做—The taxi driver is to blame for the serious accident.——出租车司机应为这起严重的事故负责。
—I can’t agree more. He shouldn’t have drunk.——我非常赞同。
他本不应该喝酒的。
(北京高考)We could have faced the difficulty together, but why didn’t you tell me?我们本可以共同面对困难,可你为什么不告诉我呢?单句语法填空1.We can’t imagine that tw o children ____________ be killed by the washing machine of their house.答案:should2.—Who is the man over there? Is it Mr. Li?—No, it ____________ be him. Mr. Li is much taller.答案:can’t3.It is required by the rules that students ____________ get grades not lower than 80 in any subject in order to win the scholarship.答案:shall4.Growing up ____________ be difficult, for we will come across many things that confuse us.答案:can5.—What a slow bus this is!—Yes, we ____________ just as well walk.答案:may/might6.Sorry, Cathy, I didn’t know that you were badly short of money then. But you ____________ have asked me for help.答案:could7.(2016·北京丰台区期末考试)Judging from his accent, he____________ not be from Australia.答案:can8.(2014·重庆高考单项填空)I’ve o rdered some pizza, so we ____________ worry about cooking when we get home tired.答案:needn’t虚拟语气用于条件状语从句中的4种情况1.虚拟语气在if条件句中的运用类别从句谓语动词主句谓语动词与现在事实相反过去式(be用were) should/would/could/might+动词原形与过去事实相反had+过去分词should/would/could/might+have+过去分词与将来事实相反过去式(be用were)should/would/could/might+动词原形should+动词原形were to+动词原形(湖南高考)Sorry, I am too busy now. If I had time, I would certainly go for an outing with you.对不起,我现在太忙了。
要是有时间,我一定与你一起去郊游。
2.虚拟条件句中的省略与倒装如果虚拟条件句中含有were/had/should, 有时可把if省略,把were/had/should提到主语之前形成倒装;若为否定形式, not不可提前。
Had he caught the morning train, he would not have been late for the meeting.要是他赶上了早晨的火车,那他就不会开会迟到了。
3.错综时间条件句有时条件句的动作与主句动作发生的时间不一致,这时动词的形式应根据它们各自表示的时间加以调整。
(北京高考)If we h ad booked a table earlier, we wouldn’t be standing here in a queue.如果我们早些订位子,现在也就不用站在这里排队了。
(if条件句是对过去的虚拟,而主句是对现在的虚拟)。
4.含蓄条件句(1)有时假设的情况不用条件句表达,而是用but for, without等介词(短语)或上下文来表示。
We wouldn’t have finished the project on time without your time ly help. 如果没有你的及时帮助,我们就不能按时完成那项工程了。
(2)用连词otherwise, or等暗示后文与前面的情况相反,从而引出后文的虚拟语气。
(3)虚拟条件通过but暗示出来,模式为“虚拟情况+but+真实情况” 。
虚拟语气用于名词性从句中的4种条件1.在“It is+important/necessary/natural/strange/essential/vital/a pity+that... ” 句型中,谓语动词用(should+)动词原形。