《大学英语情态动词》PPT课件.ppt

情态动词和助动词一样，都是辅助性的动 词，用来帮助构成不同的时态和语态， 表示说话者的某种情态，没有人称和数的 变化 may might can could shall should will would Must 无变化 1. 表示请求 Will you give her the letter? Would you please tell me your telephone number? 2.表示习惯或倾向，与used to 进行对比 Scarf used to be heavy smoker Father used not to be so forgetful 2. Would强调过去某种特定情况下的动作， 是完全过去的事情，与现在没有联系。 She used to get up at six in the morning She would get up at six in the morning Man used to think that the earth was flat Man would think that the earth was flat In those days, whenever I had difficulties, I_ Mr. Shen for help. A. Used to go to B. Was used to go to C. Would go to D. Used to going to He_up at five, but now he gets up at six. A. Used to getting B. Would get C. Was used to get D. Used to get 3.表示推测 It will be Mr. Wang knocking at the door. It would be about ten oclock when he left home They_in New York by now. A. will arrive B. will be arriving C. will have arrived D. are arriving 4. 表示命令、强迫 All will arrive before 7:45 5. 表示意愿或者固执地坚持。 She wont lend me the money The window wont open 6.表示能力（拟人化） The hall will seat 1000 people 7.表示客观事实 Fish will die out of water 8.表示意图或允诺 You will have your share 9 Would rather Would rather(sooner).than He would rather_than_the secret. A. dietelling B. dieto tell C. dead.tell D. dietell I would rather you _her the bike the other day. A. didnt lend B. hadnt lent C. should not lend D. wouldnt have lent 1）表示许可 You can borrow two books at a time from the library 2）表示可能性 I cant guess whose book it is 3）表示能力 She couldnt climb the mountain 注意： Cant help和couldnt bear中的不能变成be able to. The weather was able to clear up The fire was not able to be put out Can(could)+have+过去分词有时等于 may(might)+have+过去分词 意思为可能 Can they have missed the train He couldnt have been swimming all day She couldnt have heard you knocking at the door Have to 和 must 1)have to 强调客观需要，must强调主观看 法 I must learn another language I have to learn another language Someone must have lost the game. Someone had to lose the game 注意以下两句 Though she didnt need to , she must go. You dont have to come again, but you must 2.have to 表示义务或习惯动作，must表示重 要或急迫的事情。 We have to care for the young She has to be at the office before eight every day. You must go to the manager at once, or youll be dismissed. 3) have to 可用于不同时态，must一般只用 于现在时 I have to leave now Well have to buy another TV set They had to put off the sports meet because of the bad weather 4.must可以表示推测，have to 不能 This must be Jims pen There must be something wrong with the machine 注意: Have to 的否定式和疑问式可以按照助动词 的变化规则构成，也可以按照通用变化规 则 Have you to finish the work before supper? Do you have to finish the work before supper Must need 和 need not Must not 表示禁止, 所以在回答must 引导的 问题时，如果否定，该怎么回答？ Must needs 和needs must Needs为副词,相当于necessarily, of necessity 二者均可表示必须，必定，不得不，但 must needs 还可以表示偏偏，偏要。 I must needs go there now Needs must when the devil drives. She must needs go away when I want her. Need可以做助动词，也可以做行为动词 Father sent me the book, so I didnt need to write to him for it. Father sent me the book, so I neednt have written to him for it. She didnt need to come She neednt have come 注意:作助动词用，need只用于疑问句和否 定句，肯定句中用must, have to, should, ought to等。 Need you do it right now? I neednt, but he must. 1.表示征求意见或请求指示 Shall we meet in the evening? How shall I start the machine? 2.表示意图、意志、允诺或命令等，但shall所表示 的意志是说话人的意志，并非句子主语的意志 I shall give you a lot of money Each citizen shall carry his identification card when travelling. She shall get this paper in the evening He shall get what he deserves 1. 用于疑问句或感叹句，表示“推断” How should I know? Why should you be worrying? 2. 用在Im surpris