英语必修3第一单元Grammar.ppt

1、Unit 1,Festivals around the world,Discovering useful structures - Modal Verbs (I),热身导入 Can you list some modal verbs that you remember?,modal verbs,Can/could,May/might,Will/would,Shall/should,must,Ought to,Used to,dare,Be able to,need,Have to,情态动词的语法特征 情态动词有一定的意义，表示或暗示某种情绪或 态度，表示可能、建议、愿望、必要、允许、能力等。

2、2. 情态动词没有人称和数的变化，即不随主语的不同而变化。 3. 情态动词不能独立使用，必须和实义动词一起构成谓语。,must 表示必须， 多处于义务、责任或强制命令(must提问，否定回答用neednt或dont have to). You must hand in your homework today. (2) mustnt 表示禁止。意思是“不许”、“不准”、“不可以”。 You mustnt smoke here.,(3) 用于发生了某种于说话人的愿望相反、不受欢迎的事时，意思是“偏偏”、“偏要”。 Why must he do it that way? Why must it ra

3、in on Sunday? (4) 表示推测， 只能用于肯定句。 He must be reading novels now. The road is wet. It must have rained last night.,can /could (1)表示能力 Can you speak Japanese? (2)表示推测时，只用在否定句或疑问句中。 He cant be at home now. (3) 表示允许(许可或请求许可） You can go now, but he cant. (4) 表惊异、怀疑等 How can you be so rude? (5) 表示某人或某地一时的特

4、点，意为“可能会”,Winter can be warm in Nanchang.,can表示“能够”时与短语be able to同义，但can只用于一般现在时或过去时，而后者可用于各种时态。另外，can表示个人有某种能力，而be able to表示某人通过努力、克服困难做成某事，相当于succeed in doing sth.；叙述过去事实时，最好用was / were able to，因为could只表示过去具有某种能力。,如： Can you understand the different kinds of English these people are using? Two yea

5、rs later, he was able to speak very good Chinese.,can/could+havedone在肯定句中表示“本来可以做而实际上没做某事” ；在疑问句或否定句中表示对过去行为的怀疑或不肯定,表示推测。 Youcouldhavedonebetter,butyoudidnttryyourbest. 你本来可以做得更好，但你没努力。 Hecanthavebeentothattown. 他不可能去过那个城。,may/might (1)表示可能性，might比may可能性更小。 It may be true. He might not come today. (

6、2) 表示请求、许可，多用于肯定和疑问句中 May I ask you a question? (3) 表示愿望 May you be happy all your life. might 比 may 语气更委婉 may/might表示推测时，表示对现在或将来要发生的事情把握不大。,might/may have done表示对过去发生的动作进行的可能性推测。 He may have gone to the clinic. 他可能去医务室了。 He might have read about the news in the newspaper. 他可能已经从报纸上知道这个消息了。,will/wo

7、uld 表示意愿，will表示现在的意愿，would表示过去的意愿。 Go where you will. She asked if I would go with them. 2. 表示征求意见或提出请求，主要用于第二人称的疑问句中，will和would均可用，would此时并不表过去，而表示委婉语气。 Would Sunday night suit you? Will / Would you please post the letter for me?,3. 表示习惯和倾向性 will表示现在的习惯，would表示过去的习惯(=used to do)。 Oil will float on

8、water. When he was a child, he would often go skiing. 4. 表示推测will用于谈论现在，would可用于谈论过去，也可用于谈论现在(语气较委婉)。 Ask him. He will know. Every family would have some sort of trouble. I thought you would have finished it by now.,shall / should 1.在陈述句中,shall用于二、三人称表示允诺、警告、命令、决心等。 You shall do as I say. (命令) Nothi

9、ng shall stop me doing it. (决心) Tell him that he shall have the book tomorrow. (允诺),2. shall在疑问句中, 用于一、三人称，用来表示请求或征求意见。 Shall I open the window for you？（征求意见） Shall he fetch some water for you？（请求）,3. should常表示应当，意思和ought to相近，但语气较弱。 Young people should learn how to use computers.,5. should have don

10、e表示责备或批评,意为“本应该但” You should have told her the truth earlier. She shouldnt have left without saying a word.,4. should用于可能性推测时, 表“应该，很可能” They left at 5:30. They should get there now.,1. Jack described his father, who _ a brave boy many years ago, as a strongwilled man. （2010 安徽卷） A. would be B. woul

11、d have been C. must be D. must have been 答案：D 解析：句意为“杰克把他的父亲描述为一个意志坚强的人，他的父亲多年前肯定很勇敢”用must have been表示对过去事情的肯定推测。,高考真题,2. You _ buy a gift, but you can if you want to. （2010 湖南卷） A. must B. mustnt C. have to D. dont have to 答案：D 解析：dont have to 意为“没有必要”，符合语境，句意为：“你没有必要买礼物，但如果你想买的话，你也可以买。”,3. I have

12、told you the truth. _ I keep repeating it? （2010 江西卷） A. Must B. Can C. May D. Will 答案：A 解析： must 必须, 一定 can 可以, 能够， may 也许，will 意愿, 倾向性动作。前半句说我告诉你事实了, 这里用的是现在完成时, 表示过去的动作对现在造成了影响, 既然我已经说了, 我还必须重复一遍吗？,4. I_ have watched that movie itll give me horrible dreams. （2010山 东卷） A. shouldnt B. neednt C. cou

13、ldnt D. mustnt 答案：A 解析：句意应为“我本来不应该看那部电影的-它会使我做噩梦的。”表示“本来不应该做而做了某事”用shouldnt have done, 所以A项正确。,As he had heart attack, he was told that he _ continue the work.A. neednt B. may not C. mustnt D. cant 2. An Englishman who _ not speak Italian was once traveling in Italy. A. must B. could C. may D. might

14、 3. I _ like to make a suggestion. A. could B. would C. must D. might 4. I know things are hard with you, but you _ try to get over the difficulties.A. can B. may C. must D. ought,C,C,B,B,Choose the best answers.,5. We hope that as many people as possible _ join us for the picnic tomorrow. A. may B.

15、 must C. should D. can6. I think Ill give Bob a ring.You _. You havent been in touch with him for ages. A. will B. may C. would D. should 7. Could I have a word with you, Mum? Oh dear, if you _.A. can B. must C. may D. should,D,D,B,8. It is usually warm in my hometown in March, but it _ be rather co

16、ld sometimes. A. must B. can C. should D. would 9. You dont have to know the name of the author to find a book. You _ find the book by the title. A. must B. need C. can D. would 10. Although this _ sound like a simple task, great care is needed. A. must B. may C. shall D. should,B,C,B,11. You _ be h

17、ungry already you had lunch only two hours ago! A. wouldnt B. cant C. mustnt D. neednt 12. According to the air traffic rules, you _ switch off your mobile phone before boarding. A. may B. can C. would D. should 13. She _ have left school, for her bike is still here. A. cant B. wouldnt C. shouldnt D

18、. mustnt,B,D,A,Complete the following sentences using modal verbs.,Youve been working all day. You _ be very tired. 2. I wonder who that is. It _ be Lisa. Shes in the library at this time. 3. It is a long time since we met last time. You _ come and see us more often. 4. I havent decided where Im going for my holidays. I _ go to Australia.,must,cant,should,may,5. My fathers birthday is coming. What _ I get him? 6. Why dont you try on this dress? It _ look nice on you. 7. - Wh