《人教新课标必修三Unit1 Festivals around the world Grammar Modal verbs课件》由会员分享,可在线阅读,更多相关《人教新课标必修三Unit1 Festivals around the world Grammar Modal verbs课件(31页珍藏版)》请在金锄头文库上搜索。
1、Grammar,Modal verbs 情态动词,Unit1 Festivals around the world,情 态 动 词 的 定 义,情态动词是一种本身有一定的词义,表示说话人的情绪、态度或语气的动词,但不能单独作谓语,只能和其他动词原形构成谓语。 We can be there on time tomorrow. 我们明天能按时去那儿。 May I have your name? 我能知道你的名字吗? Shall we begin now? 我们现在就开始吗? You must obey the school rules. 你必须遵守校规。 情态动词数量不多,但用途广泛,主要有下列
2、: can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would) .,He can speak English very well. Could you please show me the way to the park? I promised that I would do my best. You ought to ask your teacher. You must be joking. That cant be true. The teacher should be
3、 there soon.,情态动词的语法特征,1)情态动词不能单独做谓语,除ought 外,后面只能接不带to的不定式。,2)情态动词没有人称,数的变化,但有些情态动词,如can、will也有一般式和过去式的变化。,3)个别情态动词有现在式和过去式两种形式,过去式可以用来表达更加客气、委婉的语气,时态性不强,可用于过去,现在或将来。,Can /could,1, 表示能力 Can you finish this work tonight? Man cannot live without air. I could ride a bike when I was 7 years old.,2,表示可能
4、性,推测。通常用在否定句疑问句以及感叹句,表达惊异、怀疑 之意,此时could不表示过去时态,只是could语气更加不肯定。 Can this be true? How can you be so careless! This couldnt be done by him.,3,表示请求或者许可,could比can更加委婉。 Can you help me? Could you give me a hand with this box. Could I use a calculator while at an exam. Yes, you can,用在肯定句中表示可能性非常小,只是一时的或者理
5、论上的客观性。 It can be very hot in our city in summer. Anybody can make mistakes.,May/might,1,表示请求或者许可,might比may更委婉。肯定回答只用may,否定回答用had better not/mustnt。 You may drive the car. Might I use your pen? No, you mustnt.,2,用于祈使句中表示祝愿。如: May you succeed!,3,表示推测、可能(不能用于疑问句)。 He may be very busy now. He may not c
6、ome today.,4,can与may表示推测区别:may用于主观的推测,用于肯定句否定句,不用于 疑问句。Can用于否定句疑问句,用于肯定句时表示一时的、理论上的推测。 May not“或许/可能不”;can not“不可能”,语气教强烈。 Can that be our headteacher? No, it cant be him. No, it may not be him.,1,表示请求、建议等,would比will委婉客气。肯定回答用will如: Would you pass me the book? yes, I will.,Will/would,2,表示意志、愿望和决心。如:
7、 I will never do that again. They asked if we would do that again.,3,表示一种习惯、倾向或趋势。Would表示过去的一种习惯倾向。 Without water, fish will die. My father would have a walk after supper.,4,表料想或猜想。will/would be对现在推测, will/would have done对已完成动作推测。如: It would be about ten when he left home. What would she be doing th
8、ere? I thought he would have told you all about it.,Shall/should,You shall do as I say. (命令) Tell him that he shall have the book tomorrow. (允诺) Nothing shall stop me doing it. (决心) Each competitor shall wear a number,2.在疑问句中,用于第一、三人称,用来表示请求或征求意见。,1.shall用于第二、三人称表示允诺、警告、命令、决心,规定等。,Shall I open the w
9、indow for you?(征求意见) Shall he fetch some water for you?(请求),3. should常表示劝告、建议、命令,与ought to意义相近,但ought to多表示责任、义务,语气强烈。在疑问句中通常用should代替ought to。,Young people should learn how to use computers. Every citizen ought to obey law. You ought not to go.,4,should可以用来表示一种估计的情况可以翻译为“按理应当,估计”,They should be the
10、re by now,I think. The poems should be out in a month at most.,5,should 可以表示惊异、不以为然等情绪,有时翻译为“竟然”,I think it is dreadful that anyone should be so miserable. I cant think why he should have said that; it was my fault. It seems so unfair that this should happen to me. Why should you talk to her like th
11、at? How should I know?,must,1,must做“必须” 讲时,否定形式用neednt或者dont have to,意思为 “不必” mustnt表示“禁止”。 Must we hand in our English exercise books? yes, you must. No, you neednt/ dont have to.,2,must表示推测,主观推测,译为“一定,肯定”, must do对现在推测,must have done对过去推 测。否定推测用cant。 He must be in the classroom now, isnt he? He mu
12、st have known our secret, hasnt he? He must have known our secret last night, didnt he?,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 neednt Must you?Yes, I must. No, I neednt. /dont have to. May I ? Yes, of course. No, you mustnt. Could you? Yes, you can. No, you cant.,情态动词+ have +过去分词,1,can/could
13、 have done 可能已经,本来可以/可能(却没有) You could have done better. I saw Mr zhu just now. He couldnt have gone to Beijing. 2,may/might have done 也许已经,本来可以/可能(却没有) He may/might have gone home. He may not have finished the work. You might have given him more help.,3,must have done一定、肯定已经 4,would have done 本来会 I
14、f you had worked hard, you would have passed the exams. 5,should have done 本来应该 You should have been more careful. You shouldnt have spoken to your mother in that way. 6,neednt have done 本来不需要 You neednt have taken your dictionary., _ I go out to play, mum? No, you _. You should do your homework fir
15、st. A. Might; wouldnt B. May; had better not C. Must; mustnt D. Need; mustnt,课堂练兵,2. Where is Emma? I cant say for sure where she is, but she _ be out shopping. A. can B. should C. must D. may 3. The room is in a terrible mess; it _ cleaned. A. cant have been B. couldnt be C. may have been D. would
16、be,4. There _ be any difficulty about passing the road test since you have practised a lot in the driving school. A. mustnt B. shant C. shouldnt D. neednt 5. This umbrella looks like mine, but it isnt. Whose _ it be? A. must B. can C. may D. might,6. May I sit beside you, sir? Sorry, you _. Look, my daughter is coming. A. cant B. mustnt