情态动词的用法.doc

Usages of Modal Verbs情态动词表示推测的用法 mustshouldcancouldmaymight （语气从强到弱）1. must所表示的可能性最大，最有把握，意为“一定”。2. can和could主要用于否定句和疑问句中，cant或couldnt 表示“不可能”。3. may和might表示现在或将来可能发生的动作或情况，主要用于肯定句中，might相对于may来说，表示的可能性更小一些。注意：1) 表示猜测，can/could一般不用于肯定句中，除非是“经验之谈”。 e.g. Anybody can make mistakes. 2) 表示猜测，may和might都不用于疑问句中。 e.g. (正) Can Could it be cloudy tomorrow？ (误) May Might it be cloudy tomorrow？即讲即练 Mary _ be in Paris, for I saw her in the town only a few minutes ago. A. mustnt B. cant C. shouldntD. may not Peter _ come with us tonight, but he isnt very sure yet. A. must B. may C. can D. will Are you coming to Jeffs party Im not sure. I _ go to the concert instead. A. must B. would C. should D. might It _ last night，for the ground was wet this morning. A. must have rained B. may have rained C. must rain D. might rain 4. should也可以用来表示“推测”，意为“可能；该”，相当于be expected to。往往指具有一定的客观根据或根据推理对现在某事发生的“可能性”进行描述，语气上不如must强。即讲即练 Will Mr Wang offer us a hand? He _ be glad to. He never refused our request. A. can B. must C. may D. should When can I come for the photos? I need them tomorrow afternoon. They _ be ready by 12：00. A. can B. should C. might D. needIts nearly seven oclock. Jack _ be here at any moment. A. must B. need C. should D. can注意： 解答情态动词表示猜测的试题时，一要清楚被猜测的时间，二要清楚有无客观事实根据。若有客观事实根据，则无论是肯定还是否定的猜测，猜测语气最强且符合时间要求的为最佳答案；若无客观事实根据，纯凭主观臆断，则猜测语气最弱且符合时间要求的为最佳答案。表示推测 情态动词的重要用法情态动词对现在对过去对将来肯定的推测must+ V.+ be doing+ have done+ V.常见must be可能的推测may, mightcould, can+ V.+ be doing+ have done+ V. 否定的推测cant,couldnt+ V.+ be doing+ have done+ V.疑问的推测can,could+ V.+ be doing+ have done+ V.即讲即练 那小女孩没有出门。她现在一定在做家庭作业。 The girl is not out. She her homework now. 路上是湿的。昨晚一定下雨了。 The road is wet. It last night. 我刚刚拜访过他。他现在一定呆在家里。 I have just dropped in on him. He at home. 你为什么没有接电话？ 我当时一定是在睡觉所以没听见。Why didnt you answer my phone call? Well, I , so I didnt hear it. 那男孩想必已经完成了他的家庭作业了。 The boy his homework.情态动词表示能力的用法情态动词表示能力时，一般用cancould或be able to。1. can常指现在，较常用；如果只表示能力时，两者都可用。 e.g. I can / am able to swim.2. be able to 可用于各种时态 e.g. We shall be able to finish the work next week. 侧重于“克服一定困难”“经过一定努力”“有能力”干某事can 只有一般现在时和一般过去时两种时态 客观上能够即讲即练 The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was able to 情态动词表示“许可”、“允许”的用法 can/could/may/might过去式could常用于疑问句中，比can更加委婉，表示礼貌。回答时，常用原形can或者may，不可再用过去式could/might。 e.g. Can/May/Could I use your pen?肯定简略回答： Yes, you can/may. Yes, please.否定简略回答： No, you mustnt. Please dont. No, you may not. 即讲即练 Could I borrow your dictionary? Yes, of course you _. A. might B. will C. can D. should其它情态动词的用法 shall和should1. shall用于第一、三人称疑问句中，表示说话人征求对方的意见和向对方请示。e.g. Shall we begin our class?（征求意见）When shall Mike be able to leave hospital?(请示)2. shall用于第二、三人称陈述句中，表示说话人给对方的命令，警告，允诺，决心或威胁。e.g. You shall go with me. (命令)You shall have the book when I finish it. (允诺)He shall be punished. (威胁)3. 用于条约，规定，规章等文件中，表示一种义务，shall多用于第三人称中。即讲即练 “The interest _ be divided into five parts, according to the agreement made by both sides.” declared the judge.A. may B. should C. must D. shall4. should= ought to 表示劝告，命令，建议，意为“应该”，而ought to 语气更强e.g. A: Ill start the work tomorrow. B: I think you should start today. C: No, you ought to start at once. (语气更强） must / have tomust“必须”，侧重说话人的主观看法have to(有多种时态）侧重于客观上的需要，含有“不得不”的意思 have got toe.g. Must I hand in my exercises now? Yes, you must. No, you neednt. No, you dont have to.注意： mustnt 不应该，不许，禁止dont have to neednt不必 will 做情态动词1. will表示请求, 建议等，不如would委婉。e.g. Will /Would you pass me the book?Will he pay for me?2. will 表示意志，愿望，决心。e.g. I will never do that again.I will give up smoking. used to和would1. 都可以表示过去重复的习惯。2. 区别： used to“过去怎样而现在却不这样了”would单纯表示过去的习惯性动作，常和often, everyday等连用e.g. He would take a walk near the forest in the evening.（现在可能散步也可能不散步了）He used to take a walk near the forest in the evening. （而现在不散步了）不能用的would的情况：1) She isnt what she used to be. 她跟过去不一样了。（表示对比，不可用would）2) There used to be a park. 以前这里有一个公园。（表示过去的状态，只能用used to，不可用would） 可兼做行为动词的情态动词：need、dare 情态动词 (+动词原形)行为动词needdare1. 无人称和数的变化；多用于肯定句； need to do dare to doneed to be done need doing2. 尤其用于：* 否定句及疑问句中；* 在if/whether之后；* 或与hardly, never, no one, nobody连用;3. 常以neednt和darent 的形式出现；4. dare有其过去时dared。e.g. We need to tell him the news. You dont need to tell him the news. Do the flowers need watering? I didnt dare to tell you the truth. Would you dare to catch the snake with your hand? The boy dares to do anything he likes.即讲即练 判断正误题：How dare you say such a thing?How dare you to say such a thing?He darent to speak English before such a crowd, did he?He darent speak English before such a crow