《情态动词ppt课件.ppt》由会员分享，可在线阅读，更多相关《情态动词ppt课件.ppt（35页珍藏版）》请在三一办公上搜索。
1、Grammar -Modal Verb,命题热点：情态动词的基本用法;情态动词表示态度的用法;情态动词表示推测的用法;情态动词在虚拟语气中的运用。,常见的情态动词有： can 能 may 可以 will，would （表意愿）need 需要 dare 敢 must 必须 have to 不得不shall，should 应该（表义务） ought to 应该,1.can，could 的用法,1）表能力，有“能”、“会”、“能够”的意思Can you drive a car? -Yes, I can. -No, I cant.,注：过去式could语气比can更加委婉 Could I use yo
2、ur car?,2）征求许可，意为“可以” Can I use your bike?(=may但没有 may 正式）,3）表示可能性，常用于否定句和疑问句 Can it be true? Today is Sunday. He cant be at school.,can 只有一般现在时和一般过去时两种时态(could)，其他时态要用be able to的形式例如：,can 和 be able to 的比较,I havent been able to get in touch with her.我一直没能和她联系上。,通常can 和 be able to 可以互换,2.may，might的用法
3、,2.1 表示许可或征求对方的许可，有“可以”的意思。例如： You may go now. May I use your computer?,注：过去式might表示的语气更加委婉、客气例如： Might I use your pen for a while?,注：回答以may开头的疑问句有如下表达法例如：-May I smoke here? 肯定 -Yes, you may 否定；-No, you cant -Yes, please -No, you mustnt. -No, youd better not.,2.3表示猜测，通常只用于陈述句 例如： You may be right. 你
4、可能是对的。,2.5 在口语中can可以代替may表示许可，但can较随便，may更正式例如： Can I use your bike, John?May I have a look at your license please, sir?,3.must 的用法,3.1表义务，“必须”例如：You must talk to them about their study.,3.2 在否定结构中表不许、禁止 例如： You mustnt smoke here.,附：关于must的回答。例如：Must I clean the dining room at once? 肯定： -Yes, you mu
5、st. （是的，你必须否定： -No, you neednt.（不，你不必 -No, you dont have to.,3.3 表坚定的建议例如： You must come and see us as soon as you get to Shanghai.,3.4 表推测，暗含有很大的可能性例如： He must be ill. He looks so pale.,注意may 暗含的可能性较小，must 暗含的可能性较大。,Have to 的疑问句和否定句，多用助动词do构成。例如：Did he have to do it?他得做那件事吗He didnt have to do it.他不
6、需要做那件事。,4.have to的用法 have to 意为“不得不”，它虽属于情态动词， 但它有人称、数的变化，其 疑问句，否定句的构成也和其他的动词有所不同。,4.1 have to & must,（1）must 强调“内在的职责”、“义务”，强调说话人的主观看法。 have to 强调“外界压力”、“不得已而为之”。 （2）have to可用于多种时态，而must一般用于现在时，其过去时与将来时分别由had to与shall / will have to代替。 （3）have to的否定式表示“不需要”， mustnt表不允许。例如： You dont have to go there
7、.你不需要去那儿。 You mustnt go there?你不准去那儿。,5.need 的用法,need 既可用作情态动词，又可用作实义动词 作情态动词时，没有数和人称的变化，后接动词原形；作实义动词时，有数的变化和人称的变化，后接带to的不定式，意为“需要做”。,其否定式为“neednt ”，表“不必”例如：You neednt worry.你不必担心。 其疑问句式为： Need +sb.+ do?，表“需要吗”例如：Need you go? 你得去吗？ -No, I neednt. 不必。 -Yes, I must. 是的，我必须去。,6.will和would的用法,will,（1）表示
8、“意愿”，I will help you. (2) 用于第二人称表征求意见， Will you have some more wine? （3）用于第三人称表推测。 -Somebody is coming upstairs. - That will be Mary. (4) 表示将来或现在的习惯。 He will come this afternoon. The old man will sit by the window for hours.,例3：Hes strange - he _ sit for hours without saying anythingshall B. will C.
9、 can D. must 分析：will用来谈习惯和特性，本句意思为“他很怪，能一坐几个小时一句话也不说”。答案为B。,2. Would (1)表示过去的意愿。I would like to see Mr. Smith2）表示过去的习惯。When I was a child, we would get up early and go climbing 3）征求意见，语气比will 委婉.Would you mind my smoking here?,7.shall和should的用法,1 shall，用于一三人称，征求意见或提议。Shall we go out for lunch?用于第二人称
10、，表一种强烈的感情，如“命令，禁止，威胁，允诺”等. If you dare do that, you shall be punished.表示规章，指示，预言等。 All shall die.,例6：You cant imagine that a well-behaved gentleman _ be so rude to a lady. (2001上海)A. might B. need C. should D. would分析：在某些名词性从句中，should 表示惊异、意外等情绪，常译为“竟然”。答案分别为C。如：It seems unfair that this should happ
11、en to me. 真不公平，这件事竟然发生在我身上。,例1：“The interest _be divided into five parts, according to the agreement made by both sides.A. may B. should C. must D. shall例2： The room is so dirty. _ we clean it? Of course. (2003北京春)A. Will B. Shall C. Would D. Do分析：上述两题均考查 shall的非常用含义，当shall用于一、三人称疑问句中时，表示征求对方意见；用于二、
12、三人称陈述句中，表示说话人给对方的命令、警告、允诺或威胁等。上述三题答案分别为D、B。,should,(1) 表示义务，责任，意为“应当” 。 You should pay for your taxes.（2）表示推测，可能性。意为“可能，应该”。 Its mid-night,he should be home.（3）用于提建议，请求， I should say it would be better to delay the meeting. (4) 表示惊讶和难以置信。 Why should he do such a thing?,例6：You cant imagine that a wel
13、l-behaved gentleman _ be so rude to a lady. (2001上海) A. might B. need C. should D. would分析：在某些名词性从句中，should 表示惊异、意外等情绪，常译为“竟然”。答案分别为C。如：It seems unfair that this should happen to me. 真不公平，这件事竟然发生在我身上。,Should “应该”，主要表示主观看法， Ought to“理应”，则更多反映客观情况，在谈到法律，规定.义务时用。如：,Should & ought to,You should finish y
14、our work first, and then watch TV.,You ought to clean the classroom , for it is your turn today.,9.情态动词表示“推测”的用法,2.情态动词+动词的完成时表示对过去情况的推测。 1) must+have +v-ed .表示过去“一定发生了.” 2) could have v-ed 表示过去 “很可能发生” 3)may / might have v-ed 表过去某事“也许”发生 4) ought to / should have v-ed意为“本来应该做” 5) neednt have v-ed 意
15、为“本没必要做”,1.情态动词+ 动词原形表示对现在的推测,1. must have v-ed,例如： 1）Since the ditch is full of water, it must have rained last night. 2）You couldnt have met my grandmother. She died before you were born.,must have v-ed 表示推测过去某事“一定”发生了。其否定形式为：cant / couldnt have v-ed, 表示过去不可能发生某事。,2 could have v-ed,could have v-ed
16、 表示推测过去某动作“很可能”发生了。 例如： Mary could have off with her friends.,3.may / might have v-ed,may / might have v-ed 表示推测过去某事“也许”发生了.may 比 might 表示的可能性稍大些。例如： I cant find my keys. I may / might have left them at the school yesterday.,4 should have v-ed,如： You should have told me the truth. You shouldnt have
17、left her alone. You ought not to have left her alone.,ought to / should have v-ed 表示“本应该”， 含有“责备”、“不满”。Shouldnt have done. / Ought not to have done 意为“本来不应该.”,5. neednt have v-ed,neednt have v-ed 意为“本没必要”。表示过去做了某事，但没有做的必要，例如：,You neednt have waken me up; I dont have to go to work today. You needn;t
18、wash these clothes for me, I can manage it.,1.A leftluggage office is a place where bags _be left for a short time, especially at a railway station. A.should B.can C.must D.will,2.How _ you say that you really understand the whole story if you have covered only part of the article? A.can B.must C.ne
19、ed D.may,3.The room is so dirty._ we clean it?-Of course. A.Will B.Shall C.Would D.Do,4.My English-Chinese dictionary has disappeared. Who _ have taken it?A. should B. must C. could D.would,5.Is John coming by train? -He should, but he _ not. He likes driving his car. A.must B.can C.need D.may,6.- I
20、 heard they went skiing in the mountains last winter. -It_ true because there was little snow there. A. may not be B. wont be C. couldt be D. mustnt be,26.I told Sally how to get here, but perhaps I _ for her.A.had to write it out B.must have written it outC.should have written it out D.ought to wri
21、te it,27.Michael _be a policeman, for he is much too short.A. neednt B. cant C. should D. may,20.The fire spread through the hotel very quickly but everyone _ get out.A.had to B.would C.was able to D.could,16.Sorry, Im late. I _ have turned off the alarm clock and gone back to sleep again.A.might B.
22、should C.can D.will,14.Are you coming to Jeffs party?-Im not sure. I _ go to the concert instead.A.must B.would C.should D.might,15.My sister met him at the Grand Theatre yesterday afternoon, so he _ your lecture.A.couldnt have attended B.neednt have attendedC.mustnt have attended D.shouldnt have attended,11.You cant imagine that a well-behaved gentlemen _ be so rude to a lady.A.might B.need C.should D.would,12.Write to me when you get home.-_.A.I must B.I should C.I will D.I can,
