1、语法对点讲练四情态动词和虚拟语气一、情态动词知识点讲解情态动词本身有一定的词义，但需和其他动词一起构成谓语。除have to, be able to外，情态动词无人称和数的变化。除have to, be able to外，情态动词只有现在时和过去时两种基本形式。除ought, used外，情态动词后面接不带to的不定式。情态动词中have to可以用have got to代替；need, dare也可用作实义动词；used to有两种否定形式：used not to和did not use to。1can, could表示具有某种能力，指有能力做某事。could表示过去的能力。表示请求和允许，
2、和may相近；口语中可用could表示委婉语气，但回答时仍用can。表示可能性，常用于否定句和疑问句中。表示惊异、怀疑、不相信的态度。特别提示“can not/never . too/enough”表示“无论怎么也不过分；越越好”。You cant be too careful when travelling alone.cannot but do sth.表示“只好；不得不”。Father cannot but agree with his daughters opinion.cant help doing sth.表示“禁不住做某事”。2be able tobe able to可以有多种时
3、态，如：将来时(will be able to)，完成时(have/has/had been able to)。be able to侧重通过努力成功做成某事的能力。He said he could swim across the river.(指本身具有这种能力)At last he was able to swim across the river.(指通过努力做到了)3may, might表示允许、许可或征求允许，否定回答时要用mustnt。might比may语气委婉。表示可能性，might比may可能性更小。may表示祝愿、愿望，常用于感叹句。特别提示may/might as well
4、do sth.“不妨；还是为好”。Everything is ready. We might as well start now.4will, would表示意志、决心或愿望。用于第二人称，表示请求、建议等。will表示“总是；惯于”。would表示过去的习惯，意为“过去常常”。表示推测或猜想。用于否定句，表示“不肯；不乐意”。特别提示表示功能、特性，意为“能；行”，多用于否定句。The door wont open.would表示提出想法，通常与like, love, hate, be glad, prefer, be happy等连用。5shall用于第一、三人称的疑问句中，表示征求对方的
5、意见或请示。用于第二、三人称的陈述句，表示说话者的命令、警告、许诺等语气。用于第三人称，在条约、规定、法令等文件中表示义务或规定，意为“应；必须”。6should, ought to表示应该，常用于表示现在或将来的责任或义务；还可表示推测，指有一定依据的推测。should还可表示惊讶，意为“竟会；居然”。Its strange that he should be absent.7must, have tomust强调主观看法，表示必须，have to强调客观需要，意为“不得不”。We must finish this work now.We will have to reconsider th
6、is plan.must表示“偏要；非得”等含义。这种用法常用于疑问句、条件句中。Must you waste so much time?must的否定形式mustnt意为“不许；禁止”；若表示“没有必要；不必”时，用neednt或dont have to。must表示推测时，仅用于肯定句，但在反意疑问句中，其后面反问部分取决于must后面的动词形式。You must be a newcomer, arent you?8need表示“需要；必须”，常用于疑问句和否定句中。肯定回答用must，否定回答用neednt。9dare主要用于否定句、疑问句以及条件句中，有过去式形式dared。10use
7、d to“过去常常”，含有今昔对比的意味，表示过去习惯的动作或状态现在已结束。而would表示过去反复发生的动作，但不含对比意味。11had better, would betterhad better表示“最好”； would better表示“宁愿；宁可”。12情态动词have donemust have done用在肯定句中，表示对过去情况的肯定推测，语气坚定。cant have done表示对过去情况表示否定的推测，是must have done的否定形式。could have done用于肯定句，表示过去本能完成但事实上并没有完成，意为“本来能够”。may/might have do
8、ne表示过去“可能发生”某事，意为“可能；或许”。should have done表示“过去本应该做某事而没有做”。shouldnt have done sth.表示“过去本不该做某事而做了”。neednt have done表示“过去本没有必要做某事而做了”。对点训练完成下列小题，并指出考查上述哪个知识点()第一组单项填空1(2013新课标卷)The door _ open, no matter how hard she pushed.A. shouldnt B. couldntC. wouldnt D. mightnt答案_C_知识点_解析句意：不管她怎么用力推门，都无法打开这扇门。sho
9、uldnt“不应该”； couldnt“主观的不能”； wouldnt“不会；不能(客观)”； mightnt“可能不”。2(2013新课标卷)Since nobody gave him any help, he _ have done the research on his own.A. can B. mustC. would D. need答案_B_知识点_解析句意：由于没人给予他任何帮助，他一定是独立做的研究。must have done对过去的肯定推测。3(2013北京卷) You neednt take an umbrella. It isnt going to rain. Well
10、, I dont know. It _ do.A. might B. needC. would D. should答案_A_知识点_解析句意：你不必带伞，天不会下雨。哦，我不知道。天也许会下雨。might“也许”，表推测，符合句意。4(2013安徽卷)It _ be the vocabulary that caused you the problem in the exercise because you know a lot of words.A. may B. couldntC. should D. neednt答案_B_知识点_解析由you know a lot of words可知不可
11、能是词汇导致的问题。couldnt“不可能”。5(2013湖南卷)He _ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.A. wouldnt B. shouldntC. couldnt D. mustnt答案_C_知识点_解析根据“尽管他努力了，但是他不能入睡”，故用couldnt。第二组语法填空6Jack, its too hot here. _ I open the window?答案Shall知识点_解析shall用于第一、三人称疑问句时，用于征求对方
12、的意见。7If the wound _ become infected, do not hesitate to call me.答案should知识点_解析should可以用于条件状语从句中表示事件发生的可能性，意为“假定要；将要”。8According to his will, his money _ be used to build a school instead of a market.答案shall知识点_解析shall用于第三人称，表示依照遗嘱、规章、法律等“必须；应该”怎么样。9It was very kind of you to do the washingup, but yo
13、u didnt _ do it.答案have_to知识点_解析句意：你真是太好了，把这些东西洗了，但是你没有必要洗的。didnt have to do表示“本没必要做”，客观上的“不必要”，动作已经发生了。10 Alice looks sad. Did you tell her about her brothers accident? Sorry, I _ (not, tell) her just before her final exams.答案shouldnt_have_told知识点_解析shouldnt have done sth.表示“本不该做某事，但是已经做了”，含有责备的意味。正
14、确答案是D项。第三组单项填空11 How can I achieve my goal? You _ work hard and stick to it.A. can B. mayC. must D. would答案_C_知识点_解析must“必须；应该”，表示强烈的劝告。12(2013漳州七校5月联考)When we worked in the same office, we _ have coffee together.A. might B. shouldC. could D. would答案_D_知识点_解析would表示过去习惯性的动作，强调过去动作的经常性。13(2013甘肃三模)Yo
15、u were stupid to try climbing up there. You _ yourself.A. can kill B. might have killedC. might kill D. must have killed答案_B_知识点_解析might have done sth.表示“过去有可能发生某事”，符合句意。must have done sth.表示对过去情况的肯定推测，意为“一定是；准是”。14(2013石家庄二模)He _ it on schedule, but somehow he fell behind.A. must have done B. might
16、 finishC. could have finished D. could finish答案_C_知识点_解析由句意可知，他没有能够完成。could have done sth.表示“本来能够做某事，而没做成”，有责备的含义，符合句意。15(2013烟台5月练习三)The weather turned out fine; I _ have taken the raincoat with me.A. wouldnt B. couldntC. mustnt D. neednt答案_D_知识点_解析天气很好，所以本没有必要带雨衣。neednt have done sth.表示“没有必要做某事却做了
17、”，符合句意。第四组语法填空16_ we go to the McDonalds? I am sick of the food there!答案Must知识点_解析must可以用来表示说话人不耐烦，意为“非要；偏偏”，往往暗示令人不愉快的事将要发生。17You _ (not) trust an online shop just because it has a beautifullydesigned website.答案shouldnt知识点_解析句意：你不应该只是因为一个网店设计漂亮就轻易相信它。must有些绝对。18The bike under the tree _ belong to P
18、eter. Look! His bag is on it.答案must知识点_解析根据“Look! His bag is on it.”可知树下那辆自行车一定是彼得的。must用于对现在情况的肯定推测。19Days later, my brother called to say he was all right, but _ (not) say where he was.答案wouldnt知识点_解析句意：几天之后，我哥哥打电话报了平安，但不愿说他在什么地方。wouldnt“不愿意；坚决不”，符合句意。20I _ (not) thank you too much for all your he
19、lp to my son while we were away from home.答案cant知识点_解析句意：我们不在家时，你对我儿子的帮助，我怎么感谢你都不过分。cant/couldnt . too .意思是“再都不为过”。21 Did you punish him for losing your digital camera? Yes, but I dont think I _ (do) that.答案should_have_done知识点_解析句意：他丢了你的数码相机，你惩罚他了吗？是的，但是我现在认为本不该这样做。答语是一个否定前移的句式， shouldnt have done表示
20、做了不该做的事。22 The work will take me another week. Im really tired. I think you _ as well consult an experienced worker. 答案may/might知识点_解析句意：这项工作还得用一周才能完成，我真的太累了。我觉得你倒不如找一个有经验的工人商量一下。may/might as well表示“还是的好；倒不如”，相当于had better。二、虚拟语气用于从句知识点讲解1虚拟语气用于if条件从句表示与现在事实相反的假设，从句谓语动词用一般过去时(be动词一律用were)。主句谓语动词用sho
21、uld/would/could/might动词原形。表示与过去事实相反的假设，从句谓语动词用过去完成时，主句谓语动词用should/would/could/mighthave done。表示与将来事实相反的假设，从句谓语动词用过去时，或were to动词原形，或should动词原形，主句谓语动词用would/could/should/might动词原形。特别提示错综时间条件句：条件从句与主句谓语动词不是同时发生。谓语动词要根据各自的时间来确定。If I at school, I ， too.If it much, the crops would .If today, we to Beijing
22、.含蓄条件句：由介词with, without, but for, in that position等，或由连词or, otherwise, and, but, but that等代替if条件句。I couldnt have finished the work on time without your help.But for your timely warning, we would have got into great trouble.省略if的虚拟条件句：当虚拟条件句的谓语动词含有were, should, had时，if可省略，而将were, should, had等词置于句首，形成
23、倒装。Were he here, everything would be alright.Should it rain tomorrow, we would put off the trip.2虚拟语气用于其他状语从句as if/though引导方式状语从句时，表示现在或将来的虚拟时，从句谓语动词用过去时(be动词一律用were)；表示过去的虚拟时，从句谓语动词用“haddone”。even if/though引导让步状语从句时，主句和从句都用虚拟语气，动词形式与if引导的非真实条件句的虚拟语气相同。in order that, so that, in case, for fear that引
24、导的目的状语从句中，谓语动词可用(should)do。Keep quiet in case you (should) interrupt him.She is now studying hard for fear that she (should) fail in the exam.3虚拟语气用于宾语从句wish后的宾语从句中：发生时间虚拟语气构成发生在主句动作前haddonewould/could/might/shouldhavedone与主句动作同时发生过去时(be用were)发生在主句动作后would/could/mightdowould rather, had rather, woul
25、d sooner之后的宾语从句中：发生时间虚拟语气构成过去haddone现在过去时(be用were)将来过去时(be用were)Id rather you had seen the film yesterday.Id rather you were here now.虚拟语气在suggest (建议), arrange, command, demand, desire, insist, order, propose, request, require等后面的宾语从句中，用(should) do形式。4虚拟语气用于主语从句在“It isadj./过去分词/n.that .”句型中，that引导的
26、主语从句中谓语动词常用“(should) do”形式。常用于此结构的词有：形容词necessary, natural, strange, important, surprising, vital等。过去分词demanded, required, desired, suggested, ordered, decided, requested, recommended等。名词duty, pity, regret, no wonder, shame等。5虚拟语气用于同位语从句和表语从句中表示“命令、建议、要求、目的和愿望”的名词后面的同位语从句和表语从句中谓语动词用“(should) do”形式。用
27、于此结构的常见名词有suggestion, proposal, demand, request, order, advice, desire等。6虚拟语气的特殊用法if only表示与现在或将来事实相反的愿望时，用过去时或would/coulddo形式；表示与过去事实相反的愿望时，用过去完成时。在“Its (high) time (that) .”句型中，从句的谓语动词常用虚拟语气表示将来的动作，动词一般用过去时或shoulddo形式，should不可以省略。对点训练完成下列小题，并指出考查上述哪个知识点()第一组单项填空1(2013北京卷)If we _ a table earlier, w
28、e wouldnt be standing here in a queue.A. have booked B. bookedC. book D. had booked答案_D_知识点_解析句意：如果我们早点预订餐桌的话，我们现在就不会站在这里排队啦。从句为与过去事实相反的虚拟语气，应用过去完成时。2(2013安徽卷)I _ to my cousins birthday party last night, but I was not available.A. went B. had goneC. would go D. would have gone答案_D_知识点_解析由but .一句知是虚拟
29、，对过去虚拟主句谓语用would have done，故选D项。3(2013浙江卷)Eye doctors recommend that a childs first eye exam _ at the age of six months old.A. was B. beC. were D. is答案_B_知识点_解析句意：眼科医生建议小孩的第一次眼睛检查应在6个月大时。recommend后接从句，从句谓语动词用should do, should可省去。4The children must have got lost in the woods; otherwise, they _ at the
30、 lakeside camp as scheduled.A. would have been B. must beC. would be D. should be答案_A_知识点_解析句意：这些孩子一定在森林中迷路了，要不然的话，他们早就该按预订的时间在湖边的宿营地了。must have done表示对过去肯定推测，由此可知空处表示与过去事实相反的虚拟语气，应用would/could/should/might have done的形式。5(2013淄博二模) I do want to see the movie. Okay, if the rain _ now, we _ to the the
31、atre.A. stops; go B. could stop; will goC. stopped; would go D. would stop; would to答案_C_知识点_解析由now可知，if从句表示与将来事实相反，谓语动词用一般过去时；主句表示与将来事实相反，谓语动词用would/could/might/shoulddo形式。第二组语法填空6 What a journey! Weve finally arrived! _ (have) we not used an outofdate train schedule, we would not have missed the t
32、rain.答案Had知识点_解析主句表示与过去事实相反，if从句应该用had过去分词，省略if后， had提到句首。Had we not used .是省略if的虚拟条件句，补充完整为“If we had not used .”。7Did your boss accept your proposal that we _ (go) to Wuyuan, the most beautiful countryside in China, to enjoy the attractive scenery?答案(should)_go知识点_解析proposal后的同位语从句中应使用虚拟语气，即从句中谓语动
33、词用(should)do形式。8It is required that the students _ (not, use) mobile phones in their school.答案(should)_not_use知识点_解析句意：学校要求学生在校内不准使用手机。It is requiredthat从句，从句谓语应用“shoulddo”， should可以省略。9John wants to see me today. I would rather he _ (come) tomorrow than today.答案came知识点_解析句意：约翰想今天来看我。我宁愿他明天来看我而不是今天。
34、在would rather后的宾语从句中，其谓语动词用一般过去式表示对现在或将来的虚拟。10He opened his lips as if he _ (say) something to you.答案would_say知识点_解析句意：他张开嘴好像要对你说什么。分析句意可知， as if后面的句子需要使用虚拟语气，并且所述内容是对将来情况的虚拟，谓语应用“would动词原形”。第三组单项填空11There is nothing the matter. I wish you _ me about it.A. might bother B. should botherC. wouldnt bot
35、her D. dont bother答案_C_知识点_解析句意：不要紧，请别为我操心。wish后的宾语从句表示与将来事实相反的愿望，从句谓语用“could/would/might动词原形”，且结合句意，应用否定形式，故选C项。12It is already 8 oclock. It is high time that we _ out.A. should start B. startC. would start D. will start答案_A_知识点_解析句意：已经8点钟了。我们该出发了。It is high time that .句型中，从句的谓语用一般过去时或“should动词原形(其
36、中should不能省略)”，故选A项。13(湖南卷)Sorry, I am too busy now. If I _ time, I would certainly go for an outing with you.A. have had B. had hadC. have D. had答案_D_知识点_解析从前句可知“我”很忙，后面的句子只是一种假设，是一个含条件状语从句的虚拟语气，是对现在的虚拟， if从句中谓语动词用过去时形式。14(安徽卷)Grace doesnt want to move to New York because she thinks if she _ there,
37、she wouldnt be able to see her parents very often.A. lives B. would liveC. has lived D. were to live答案_D_知识点_解析句意：格雷丝不想搬到纽约去，因为在她看来，如果她住在那里的话，她就不能经常看到父母了。这是一个含对将来情况提出假设的虚拟语气， if条件状语从句用“were to动词原形”，当然也可以用过去式(be的过去式用were)，但A、B、C三项均不符合。15 Lets play football together tomorrow afternoon. OK, but how I w
38、ish I _ it as skillfully as you.A. played B. have playedC. had played D. will play答案_A_知识点_解析wish宾语从句中使用虚拟语气时，表示与现在事实相反，用过去时。16Tom suggested that I _ wrong and that I _ it out in another way.A. should be; should workB. was; workedC. was; workD. be; work答案_C_知识点_解析suggest作“暗示；启发”解，后接that从句， that从句谓语动词不用虚拟语气，该句主句的谓语动词用的是一般过去时，宾语从句也使用一般过去时，但是从第二个宾语从句的意思看， suggest是“建议”的意思，从句用虚拟语气，由“should动词原形”构成，should可省略。
