高三英语情态动词复习课件

3.对目前正在发生的事情进行推测： 句式：must/may/might/can/could＋be doing They must be waiting for us. 他们肯定正在等我们。 She may/might be doing her homework. 她可能正在做作业。 Can/Could he be playing football? 他会正在踢足球吗？
II 情态动词在一般疑问句的问与答
1. Need I…? Yes, you must. No, you needn’t. 2. Must I…? Yes, you must. No, you needn’t . (No, you don’t have to./ No, you haven’t got to.) 3. May I…? Yes, you may. (=Yes, certainly / of course.) No, you may not. (No, you can’t / mustn’t.)
6. could have done 表示本能够做到某事，却没 有做到，所表示的是与事实相反的情况。 We could have finished the work ahead of time. 我们本来是能够提前完成工作的。 7. couldn’t have done 表示本不能够做到某事， 却做到了，所表示的是与事实相反的情况。 We couldn’t have finished the work ahead of time without your help.
III 情态动词表示“推测”的用法
1.can,may,must使用的句式： 1)肯定陈述句中：must表“肯定、必定、一定”意， may/might表“也许，或许”意。 2)否定陈述句中：can’t/couldn’t表“不可能”意， may not/might not表“也许不、可能不”意。 3)疑问句中：只能用can或could,不能用must,may 或might。 注意：表推测的could, might并不是指过去时间 并不是指过去时间， 注意：表推测的could, might并不是指过去时间， 而是表示比can, may把握性略小些的情况。 而是表示比can, may把握性略小些的情况。 把握性略小些的情况
2. will 的用法： (1) 在疑问句中，用于第二人称，用来征询对方意见或请求指 示。 Will you please do some shopping with me? (2) 用在各人称中，表示“意愿、愿意”。 Come on, children. I will tell you all about my story. (3) 用于各人称，表习惯性或规律性，意为“总是、惯于”。 Man will die. (4) 用在 Let us do sth. 或否定祈使句 Don’t do sth. 后的反意疑问 句中。 Let us start now, will you? Don't shut the door, will you? (5) will 的否定式（won’t）还可表示某东西总是或老是有不妙 的情况发生。 The door won’t close.
8. can’t / couldn’t have done 表示对过去发生的 事情的否定推测。 They can’t have gone skiing last winter, for there was little snow in the mountain. —There were five people in the car, but they managed to take me as well. —It couldn’t have been a pleasant journey.
4. Shall I…? Yes, please. No, thanks. / No, you needn’t .(委婉) / No, you can’t .(反对) / No, you mustn’t. (禁止) 5. Could I…? Yes, you can. / No, you can’t. 6. Might I…? Yes, you may. / No, you may not.
V will和shall, dare和need的用法
1. shall 的用法： (1) 在疑问句中，用于第一、第三人称，用来征询对方意见或 请求指示。 Mr. Smith wants to see you, manager. Shall he wait outside or in the office? (2) 用在第二、第三人称之后表示说话人的“许诺、警告、命 令、威胁”等意愿。 You shall have the story-book as soon as I finish reading it. (3) 用在 Let’s do sth. 的反意疑问句中。 Let’s go swimming, shall we? 注意： 的反意问句， OK? 注意：Let’s not do sth. 的反意问句，常用 all right 或 OK? It’s raining hard. Let’s not go out, all right (OK)?
4. need 情态动词的用法 用在否定，疑问或条件从句中。 You needn’t go and tell her about it. Tom has told her. 附：need 实义动词的用法： (1) 作“需要”讲，后接名词或代词。 I badly need a haircut now. (2) 作“需要”讲，后接动名词的主动式或动词不定 式的被动式。 The little child needs to be operated on at once. (3) 作“需要”讲，后接复合结构。 Doctor, I need my bad tooth out. (4) 作“需要”讲，后接不定式。 Tomorrow is Sunday. You don’t need to arrive early.
3. dare 情态动词的用法： I dare not do that, or I’ll be beaten by my father. 附：dare 实义动词的用法： 肯定句中，常用 dare to do sth. 结构；否定句中，常 用 …not dare (to) do sth.结构（否定句中的不定式符 号 to 可以省略）。 It is time that we should dare to have a try. 试译：①你敢穿过那片森林吗？ Dare you go through the woods? ②他不敢向爸爸要零花钱。 He dare not ask his father for pocket money. He dared not ask his father for pocket money. He didn’t dare (to) ask his father for pocket money. He doesn’t dare (to) ask his father for pocket money.
VI 几组词语辨析
1.must与have to must强调说话者的主观看法， have to强调客观需要，表示“不必”意要用 needn’t或don’t have to, 或haven’t got to不能用 mustn’t。 I have stayed too long. I must go. It’s getting late. I have to go now.
3.can 和be able to 1）can could 表示能力；可能 (过去时用could), 只用于现在式和过去式(could)。be able to可以用于各种时态。 They will be able to tell you the news soon. 他们很快就能告诉你消息了。 2）只用be able to a. 位于助动词后。 b. 情态动词后。 c. 表示过去某时刻动作时。 d. 用于句首表示条件。 e. 表示成功地做了某事时，只能用was/were able to， 不能 用could。 He was able to flee Europe before the war broke out. = He managed to flee Europe before the war broke out.
2.对目前状态的推测： 1)must/may/might/can/could＋be＋表语 She must be a teacher.她肯定是老师。 She can’t/couldn’t be a doctor.她肯定不是医生。 He may not/might not be a doctor. 他可能不是医生。 2)must/may/might/can/could＋一些不能用于进行时 的静态动词(如:have,exist,live,like,hate,own,belong to 等) She must have her own car, for she has a lot of money. That kind of bird may live in the valleys.
5. may (might) have + done sth, can (could) have + done sth 表示过去，推测过去时间里可能 发生的事情。 Philip may have been hurt seriously in the cΒιβλιοθήκη Baidur accident. He might have gone to Nanjing with Professor Wang last week, but he was ill.
2. may和might 和 1）表示允许或请求；表示没有把握的推测；may 放 在句首，表示祝愿。 May God bless you! He might be at home. 注意： might 表示推测时，不表示时态。只是可能性 比may 小。 2）成语： may/might as well，后面接不带to 的不定式， 意为"不妨"。 If that is the case, we may as well try.
情态动词复习
I 情态动词的语法特征
1） 情态动词不能表示正在发生或已经发生的事情， 只表示期待或估计某事的发生。 2） 情态动词 除ought 和have 外，后面只能接不带to 的不定式。 3） 情态动词没有人称，数的变化，即情态动词第三 人称单数不加-s。 4） 情态动词没有非谓语形式，即没有不定式，分 词，等形式。
IV情态动词＋不定式完成式的结构和用法
1.must have done 一定做了……， 表示对过 去情况极大把握的推测。 There’s no light in the room. They must have gone to bed. 2. should / ought to have done， 表示本应该做 某事却没有做到，含有批评、责备的意思。 You should have come here a little earlier. I ought to have sent him to school.
3. shouldn’t have done / oughtn’t to have done 表示本不应该做某事却做了某事,也含有批 评、责备的意思。 He ought not to have thrown the old clothes away. 4. needn‘t have done sth表示本没必要做某事， 却做了某事。 I dressed very warmly for the trip, but I needn't have done so. The weather was hot.