高考英語一輪復(fù)習(xí) 語法精講系列 講座五 情態(tài)動(dòng)詞和虛擬語氣課件.ppt

,語法精講系列,講座五 情態(tài)動(dòng)詞和虛擬語氣,一、情態(tài)動(dòng)詞 考點(diǎn)一 情態(tài)動(dòng)詞的基本用法 1can和could的用法 (1)表示“能力”。 No one can be compared with Yao Ming in playing basketball. Oh，you are really his big fan. 在打籃球方面，無人能與姚明相媲美。 你真是姚明的鐵桿粉絲。,(2)表示禮貌地請(qǐng)求別人做某事或允許別人做某事，意為“能，可以”。 What should I wear to the party? Well，it isn't very formal.You can wear whatever you like. 晚會(huì)我應(yīng)該穿什么？ 晚會(huì)不太正式，你可以穿自己喜歡的任何衣服。 (3)表示驚訝，常用在否定句和疑問句中。 How could you do such a silly thing? 你怎么能做那樣的蠢事呢？,2may和might的用法 (1)may和might表示“許可”。 May I take the book out? I'm afraid not. 我能將書帶出去嗎？ 恐怕不行。 (2)You may come if you wish. 你想來就來吧。,3must的用法 (1)表示必要性，意為“必須”。 The children must be back by 4 o'clock. 孩子們必須4點(diǎn)鐘以前回來。 Shall I inform him of the change of the schedule right now? I am afraid you must，in case he comes late for the meeting. 我現(xiàn)在通知他日程表的變動(dòng)嗎？ 恐怕你必須通知他，以免他開會(huì)遲到。 (2)表示禁止(用于否定句)。 You mustn't park here！It's an emergency exit. 你不可以在這兒停車！這是緊急情況出口處。,4shall和should的用法 (1)shall的用法 用于第一、第三人稱疑問句中，表示說話人征求對(duì)方的意見或向?qū)Ψ秸?qǐng)示。 Shall I go out for a walk after supper? 晚飯后我可以散散步嗎？ shall與第二、三人稱連用，用于陳述句中，表示說話者的意志，用來表達(dá)說話者給對(duì)方以命令、指示或允諾。此外，當(dāng)宣布法律、規(guī)定時(shí)，也用shall來表達(dá)。如：,Will you read me a story，Mummy? OK.You shall have one if you go to bed as soon as possible. 媽媽，給我講個(gè)故事好嗎？ 好，如果你盡快上床睡覺，我就給你講一個(gè)。(允諾) It has been announced that candidates shall remain in their seats until all the papers have been collected. 已宣布，在所有試卷收上來之前，應(yīng)試者必須留在自己的座位上。(規(guī)則或規(guī)定),(2)should的用法 should意為“(義務(wù)上)應(yīng)該”，在語氣上比must(必須)弱?！皊hould動(dòng)詞原形”表示現(xiàn)在或?qū)響?yīng)該。如： I should go and visit him this afternoon，but I wonder if I will be free. 今天下午我應(yīng)該去看望他，但我不知道我是否有空。(表示將來應(yīng)該) The children should be taken good care of. 這些孩子應(yīng)該受到好的照顧。,5will和would的用法 (1)表示意志、意愿和決心，would用于過去的情況。 I have told him again and again to stop smoking，but he will not listen. 我已再三告訴他戒煙，但是他就是不聽。 You can stay here as long as you can，if you will. 如果你愿意，你能在這里待多長(zhǎng)時(shí)間就待多長(zhǎng)時(shí)間。(表示主語的意愿) Mr.Gordon asked me to remind you of the meeting this afternoon.Don't forget it! OK，I won't.(表示決心) 戈登先生讓我提醒你今天下午有會(huì)議。可別忘了！ 好的，我不會(huì)忘的。,(2)will(won't)可用來敘述真理，還可敘述目前的習(xí)慣，would(wouldn't)可以用來敘述過去的習(xí)慣。如： Oil will float on water. 油能浮在水面上。 Engines won't run without lubricants. 沒有潤(rùn)滑劑發(fā)動(dòng)機(jī)就不能運(yùn)轉(zhuǎn)。 She will listen to records alone in her room for hours. 她獨(dú)自一人在屋里聽唱片，常常一聽就是幾個(gè)小時(shí)。 He would spend hours in the bathroom or on the telephone. 他以前一進(jìn)洗澡間或是一打電話，往往就是幾個(gè)小時(shí)。,特別注意：would和used to都可表示過去的習(xí)慣，但前者表示過去反復(fù)的動(dòng)作，常與every day，often，frequently等連用；后者表示過去的狀態(tài)或過去的習(xí)慣，但現(xiàn)在已不存在。如： When he was abroad，he would read as many books as possible.在國(guó)外時(shí)，他總是盡可能多讀書。 She doesn't get up so early as she used to. 她不像以前那樣起得那么早了。,6need和dare的用法 need和dare兩者既可用作情態(tài)動(dòng)詞也可用作實(shí)義動(dòng)詞。作實(shí)義動(dòng)詞時(shí)，有人稱和數(shù)的變化，可用于肯定句、否定句或疑問句中，構(gòu)成否定句或疑問句時(shí)要用助動(dòng)詞do，does，did；作情態(tài)動(dòng)詞時(shí)，沒有人稱和數(shù)的變化，直接接動(dòng)詞原形，只用于否定句和疑問句中，構(gòu)成否定句和疑問句時(shí)不用助動(dòng)詞。 另外，dare作情態(tài)動(dòng)詞時(shí)，還可用于條件句中，過去式為dared；作實(shí)義動(dòng)詞時(shí)，dare常用于疑問句或否定句，后面的to也可省略；I dare say是習(xí)慣說法，意為“我想，大概”。如：,He needn't do it.(情態(tài)動(dòng)詞) He doesn't need to do it.(實(shí)義動(dòng)詞) 他不必做這件事。 I didn't know whether he dared say that to him.(情態(tài)動(dòng)詞，有時(shí)態(tài)變化) 我不知道他是否敢對(duì)他說那話。 He didn't dare(to) do it.(實(shí)義動(dòng)詞) He dared not do it.(情態(tài)動(dòng)詞) 他不敢那么做。,考點(diǎn)二 情態(tài)動(dòng)詞表示推測(cè)的用法 1can用于肯定句中表示客觀的可能性，意為“有時(shí)會(huì)”。 Accidents can happen on such rainy days. 這樣的多雨天氣可能會(huì)發(fā)生事故。(客觀的可能性) can用于否定句中表推測(cè)時(shí)，語氣較強(qiáng)。如： After what had happened he could not continue to work there. 鑒于所發(fā)生的事情，他不可能繼續(xù)在那里工作下去了。 You can't mistake their car；it's got a bright red line all over it. 你不可能會(huì)認(rèn)錯(cuò)他們的車，那輛車上有道亮紅色的條紋。 can，could在疑問句中，常表示困惑、不相信等。如：,There's someone outsidewho can it be? 外面有人會(huì)是誰呢？ What can they be doing? 他們可能在干些什么呢？ Could he be serious? 他當(dāng)真是這個(gè)意思嗎？ Where can she have put it? 她能把它放在哪兒呢？,2may/might用于肯定句中可以用來表示不十分肯定的推測(cè)，意為“有可能”；用于否定句中也可以表示推測(cè)，may not意為“可能不”，表示一種不太確定的語氣。 The traffic is heavy these days.I might arrive a bit late，so could you save me a place? 這些天交通很繁忙，我可能會(huì)來晚一點(diǎn)兒。請(qǐng)你幫我保留個(gè)位置好嗎？,3must表示推測(cè)時(shí)只能用于肯定句中，意為“一定，必定”，表示十分肯定的語氣(在疑問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. 這是辦公室！所以你一定知道這里不許吃東西。 噢，對(duì)不起。 4should用來表示推測(cè)時(shí)意為“應(yīng)該”，即含有“按道理來說應(yīng)當(dāng)如此”的意思。 There shouldn't be any difficulty passing the road test since you have practised a lot in the driving school. 因?yàn)槟阍隈{校訓(xùn)練了那么多，通過路考應(yīng)該沒什么困難。,考點(diǎn)三 情態(tài)動(dòng)詞的特殊用法 1cannot butdo sth.表示“不得不/只好做某事”。如： I could not but admit that he was right and I was wrong. 我不得不承認(rèn)他對(duì)了，我錯(cuò)了。 I cannot choose but go. 我只好去。,2cannot/can never.enough/too.表示“再也不為過”。 You cannot be careful enough to cross the road. 過馬路時(shí)你怎么小心都不為過。 3may可以用于祈使句，表示祝愿。如： May we never forget each other. 愿我們彼此永不相忘。 May you return in safety. 愿你平安歸來。,4may well和may as well結(jié)構(gòu)。 (1)“may well動(dòng)詞原形”是一種常用結(jié)構(gòu)，意為“完全能，很可能”，相當(dāng)于“be very likely to do”。如： He may well be proud of his son. 他大可為他的兒子感到自豪。 Her appearance has changed so much that you may well not recognize her. 她的模樣變化太大，你很可能認(rèn)不出她了。 (2)“may as well動(dòng)詞原形”意為“最好，倒不如”。如： You may as well do it at once. 你最好馬上就做這件事。 We may as well stay where we are. 我們留在現(xiàn)在的地方倒也不錯(cuò)。,5“should”有時(shí)表示說話人對(duì)某事不能理解，感到意外、驚異等，意為“竟會(huì)”。如： It's odd that she should think I would want to see her again. 她竟然認(rèn)為我會(huì)想再次見到她，真奇怪。 6must表示“偏要、硬要”。如： If you must go，at least wait until the storm is over. 如果你偏要走，你至少要等到暴風(fēng)雨停止。 Must you make so much noise? 你非得弄出這么大聲響嗎？,考點(diǎn)四 “情態(tài)動(dòng)詞have done”的用法 1should/ought tohave done表示“過去本應(yīng)該做而(實(shí)際)沒有做的事情”，含有責(zé)備或遺憾的語氣，意為“本應(yīng)該”。其否定形式為“should not/ought not tohave done”，表示某種行為本不該發(fā)生但實(shí)際上發(fā)生了。 You ought to have done this exercise more carefully. 你本應(yīng)該更仔細(xì)地做這個(gè)練習(xí)。 You shouldn't have told her the truth. 你本不該告訴她真相。,2musthave done，用于肯定句，表示“過去一定做過某事”，是一種很有把握的推測(cè)。注意：對(duì)過去發(fā)生的情況的否定推測(cè)常用“can't/couldn'thave done”表示。 Ye Shiwen won two gold medals in London Olympic Games. She must have gone through tough training. 葉詩文在倫敦奧運(yùn)會(huì)上獲得了兩枚金牌。 她肯定受過嚴(yán)格的訓(xùn)練。 It must have rained last night，for the road is quite muddy. 昨晚一定下雨了，因?yàn)槁泛苣酀簟?3may/mighthave done是對(duì)過去情況的一種不太有把握的推測(cè)，表示“可能已做了某事”，否定句表示“可能還沒有”。 Sorry，I'm late.I might have turned off the alarm clock and gone back to sleep again. 對(duì)不起，我遲到了。我可能把鬧鐘關(guān)掉后又睡著了。 4couldhave done表示“過去本來可以做，但實(shí)際上沒有做”；can/couldhave done表示“過去可能做過”。 I could have saved the poor rabbit，but I didn't have the right drugs with me at that moment. 我本來可以拯救那只可憐的兔子的，可是我當(dāng)時(shí)沒有合適的藥品。,5needn'thave done表示“過去沒有必要做某事，但實(shí)際上做了某事”。 Mark needn't have hurried.After driving at top speed，he arrived half an hour early. 馬克本沒必要那么匆忙。他以最快速度開車，結(jié)果早到了半個(gè)小時(shí)。 You needn't have taken a taxi here，for it was very near to my house. 你本來不必打車來這里的，因?yàn)檫@里離我家很近。,二、虛擬語氣 考點(diǎn)一 虛擬語氣在條件句中的用法 1if條件句,(1)與現(xiàn)在事實(shí)相反 If I were you，I should seize the chance to go abroad. 如果我是你，我就抓住這次出國(guó)的機(jī)會(huì)。 (2)與過去事實(shí)相反 If you had taken my advice，you would not have failed in the exams. 如果你早聽了我的建議，你考試就能通過了。 (3)與將來事實(shí)相反 If he should not come tomorrow，we should put off the meeting till next Monday. 如果明天他不來，我們就把會(huì)議推遲到下周一。,2錯(cuò)綜時(shí)間條件句 當(dāng)條件狀語從句表示的行為和主句表示的行為所發(fā)生的時(shí)間不一致時(shí)，被稱為“錯(cuò)綜時(shí)間條件句”，動(dòng)詞的形式要根據(jù)它所表示的時(shí)間做出相應(yīng)的調(diào)整。 I actually believe that we would be in Xi'an now if you hadn't been caught drunk driving last month. 事實(shí)上，我認(rèn)為如果上個(gè)月你沒因酒駕被逮住的話，我們現(xiàn)在就在西安呢。 特別注意：如果虛擬條件句中含有were/had/should，有時(shí)可把if省略，將were/had/should提至主語之前，形成倒裝句。否定形式的not不可提到主語前。,Had you taken my advice，you wouldn't have failed in the examination. 如果你聽了我的建議，你就不會(huì)考試不及格了。 Should it rain tomorrow，we would have to cancel the football match. 如果明天下雨，我們將不得不取消足球賽。 Were it not for the expense，I would go abroad now. 如果不是因?yàn)橘M(fèi)用問題，我現(xiàn)在就出國(guó)了。 3含蓄條件句 有時(shí)假設(shè)的情況并不用條件從句表示，而是由otherwise，if only，but，or，without，but for等來引導(dǎo)或者通過上下文表示。 If only I had taken your advice. 我要是聽了你的建議就好了。,But for your help，we couldn't have finished the work ahead of time. 沒有你的幫助，我們是不可能提前完成這項(xiàng)工作的。 He telephoned to inform me of your birthday，or/otherwise I would have known nothing about it. 他打電話通知了我你的生日，否則，我對(duì)此一點(diǎn)兒都不知道。 I would have come sooner but I didn't know that they were waiting for me. 我本該早一些到，但我不知道他們?cè)诘任摇?I wish (that) I were a bird and could fly freely in the sky. 我希望我是只小鳥，能在天空自由飛翔。 I wish(that) I had met that film star yesterday. 我希望昨天見到那個(gè)影星了。 How I wish it weren't raining now. 我多希望現(xiàn)在沒下雨啊。,(2)用于表示建議、愿望、命令等動(dòng)詞后的賓語從句中，常見的動(dòng)詞有：demand，order，require，insist，suggest，propose，advise，request，urge，command，prefer，desire，recommend等。賓語從句中的虛擬語氣結(jié)構(gòu)為“should動(dòng)詞原形”，should可以省略。如： He suggested that we(should) start off early the next day. 他建議我們第二天早點(diǎn)出發(fā)。 They insisted that the boy(should) go with them. 他們堅(jiān)決主張那個(gè)男孩子跟他們一起去。,此類動(dòng)詞記憶小竅門： 一堅(jiān)持(insist) 二命令(order，command) 三建議(advise，suggest，propose) 四要求(require，request，demand，desire),特別注意：當(dāng)suggest表示“暗示，表明”之意，insist表示“堅(jiān)持說”之意時(shí)，suggest/insist后的賓語從句不使用虛擬語氣，應(yīng)使用陳述語氣。如： The smile on his face suggested that he was satisfied with our work. 他臉上的微笑表明他對(duì)我們的工作很滿意。 The man insisted that he had never stolen the money. 那個(gè)人堅(jiān)持說他沒有偷錢。,2虛擬語氣在主語從句中的用法 It is desired/suggested/proposed/recommended/necessary/important/ strange/natural/a pity/essentialthat從句，從句的謂語動(dòng)詞用“should動(dòng)詞原形”，should可以省略。如： It is suggested that the meeting (should) be put off till next week. 人們建議會(huì)議推遲到下周。 It is strange that he (should) have acted toward his parents like that.(從句謂語動(dòng)詞的動(dòng)作在主句謂語動(dòng)詞的動(dòng)作之前發(fā)生時(shí)，要用“should have過去分詞”) 真奇怪他竟然那樣對(duì)他父母。,3用于表語從句和同位語從句中 在suggestion，proposal，order，plan，idea，request，advice等名詞后的表語從句和同位語從句中要用虛擬語氣，其構(gòu)成是“should動(dòng)詞原形”，should可以省略。如： My idea is that we (should) think it over before accepting it. 我的意見是在接受之前我們要反復(fù)考慮。 We all agreed to his suggestion that we (should) go to Dalian for sightseeing. 我們都同意他讓我們?nèi)ゴ筮B旅游的建議。,4虛擬語氣在定語從句中的用法 在It is(high/about)time (that)句型中，定語從句中的謂語動(dòng)詞用過去式，或用should動(dòng)詞原形(should通常不省略)。此句型意為“(現(xiàn)在)該”，用來表示提議。 It is (high) time that you went to school. 你該去上學(xué)了。 5as if/as though引導(dǎo)的表語從句和方式狀語從句常用虛擬語氣 He stood up and offered her his seat，as if he had read her mind. 他站起來給她讓座，他好像讀懂了她的心思。,特別注意：如果表示的事情可能會(huì)發(fā)生，那么從句中的謂語動(dòng)詞可用陳述語氣。 It looks as if it's going to rain. 天看上去似乎要下雨。,