高中英语 Unit1 Grammar课件1 重庆大学版必修3.ppt

1、Grammar,Modal Verbs ()must, may, should, will, have to,Studying the Rule,1) A: Its hot, isnt it? B: Yeah, but it may rain tomorrow. 2) A: May I sit on this chair? B: No, you mustnt. A: Why not? B: Because it is broken.,3) A: The flight to New York should be leaving in a few minutes. B: Are you sure?

2、 4) A: Sally, you should be careful when you go out at night. B: OK, I will.,5) A: I have just walked 5 kilometers! B: You must be very tired now. 6) A: Will you give this to Elle, please? B: With pleasure. 7) A: Its raining cats and dogs outside. B: Really? Then I have to take an umbrella with me.,

3、8) A: Must I hand in the homework now? B: No, you dont have to. You may hand it in tomorrow morning. 9) A: When are we going to leave the hotel? B: We must leave the hotel before 6:00 pm.,总结,1. must与have to的区别 have to比较强调客观需要, must着重说明主观看法。另外have to能用于更多时态, 比较下面的句子：,We had to be there at 10:00. 有时两者

4、都可以用, 意思差别不大。 e. g. We must/have to leave now. must在表示说话人对事物的推测时候要注意它比may肯定得多, 相当于汉语的“一定”或“准是”。(只有在肯定句中能这样用。),This must be your room 在回答由must引起的问题时, 如果是否定的答复，不能用mustnt, 而需要用neednt或dont have to, 因为mustnt是“一定不要”的意思。,2. may的用法: a. 表示“允许”或“请求”。 e. g. May I come in？,在使用这一用法时需注意: may表示“允许”的否定形式是must not,

5、意思是“不应该” “不许可”。e. g. May I take this book out of the reading-room？ No, you mustnt b. 表示说话人的猜测，认为某一事情“或许”或“可能”发生。,e. g. He may know the answer c. may用在感叹句中可表示祝愿、愿望。 e. g. May you succeed(祝你成功。) May you have a pleasant journey(一路平安。),3. should是shall的过去式，它可以用于过去时态中，但更多的是用作情态动词，意思是“应当；应该”，用来表示义务或责任。此时，它

6、不再局限于和第一人称的代词连用，而是三种人称都能使用。例如：,You should answer my question in English. 你应当用英语回答我的问题。 They shouldnt be so careless. 他们不该如此粗心。 Its raining hard. You should drive slowly. 雨下得很大。你开车要慢些。,should还可以用在提供帮助、提出建议、要求、给予指示的句子中。例如： Should I help you carry the basket? 要不要我帮你提篮子？ What should I do for them? 我应当为他

7、们做些什么？ 应当注意的是，当should表示上述两种意思时，要重读。,4. will 情态动词aux.(客气提问)是否愿意；好吗 wordthatyousaywhenyouaskapolitequestion Willyoupassthesalt? 请你把盐递给我，好吗？,Willyoupleasegivehimamessagewhenyouseehim? 你见到他时捎个口信给他好吗？ Wontyoucomeinandhavealittletea? 要不要进来喝点茶？ Willyoupleaselendmeyourrubber? 请借给我你的橡皮好吗？,表推测,1.must（一定）只用于肯定

8、句中, He looks so pale. He must be ill. 2.can / could用于肯定、否定、疑问句中, It cant be Mr. Wang . He has left here. 3.may / might可用于肯定、否定句中 There may be some dangerous animals on the island. 4.should（想必） They should be there by now.,5.如果对过去发生的事情的推测要用完成时。 Someone must have opened the cage. The lion couldnt have

9、 escaped on its own. 准是有人把笼子打开了，狮子不可能自己跑出来。,一般疑问句的肯、否定回答,1.Can you? 2. May you? Yes, I can. Yes, I may. No, I cant. No, I mustnt. 3.Must you? 4. Need you? Yes, I must. Yes, I must. No, I neednt. No, I neednt. No, I dont have to No, I dont have to. .,could, might, would等过去式用在疑问句表语气委婉时，其回答要用原形。 -Could

10、 you tell me whats the matter with you? -Yes, I can. Sure./ Certainly/ Of course.,Finding the Rule,Giving advice Saying that something is necessary Politely asking someone to do something Asking someone for permission to do something Saying that perhaps something will happen,_ _ _ _ _,4,7,6,2,1,6) S

11、aying that sth. will almost certainly happen, as long as nothing unexpected stops it 7) Expressing an opinion about something that the speaker is not sure about. 8) Expressing obligation(义务) and duties. 9) Expressing need.,3,5,8,9,_,_,_,_,A: Do we have to finish this job today? B: Yes, you_. 2) If i

12、t is raining, you _ take an umbrella with you. 3) Excuse me, but _ I ask you a very personal question? 4) I cant be sure, but I _ be late this evening. So dont wait for me.,Applying the Rule,Complete the following sentences with may, should, must, will or have to.,must,should/ must,may,may,5) A:You

13、dont _ return the book now. You can keep it until next Monday if you like. B:Thank you very much. 6) The train _ be here any minute now but you never know. 7) Excuse me, but _ you please stay off the grass. He _ stay at home because his right leg is broken. Listen! You really _ give this to Mary! It

14、s very important.,have to,should,will,has to,must,1) Ask your teacher for permission to leave school early tomorrow.,Applying the Rule,Make sentences by using may, should, must will or have to, based on the following situations .,May I leave school early tomorrow?,2) Advise your friend to study hard

15、er.,You should work harder.,3) You are a doctor. Tell a patient that it is really necessary to take all the medicine.,4) Someone asks you the time. You havent got a watch but youre sure its ten oclock.,You have to take all the medicine.,It should be ten oclock.,5) Someone ask you if it will rain tom

16、orrow. You dont know. But it is possible.,6) You phone is ringing . You are busy. Politely ask a friend to answer it.,I have no idea. But it may rain tomorrow.,Will you please answer the phone for me?,The plane should arrive at 12:00 pm, if nothing goes wrong.,7) You are a stewardess. A passenger wa

17、nts you to tell him/her the arrival time in Paris. You tell him/her the plane will almost certainly arrive at 12:00 pm, if nothing goes wrong.,8) Your son is alone at home. So you tell your friends at the party you need to go home now.,Im afraid I have to leave now because my son is alone at home.,S

18、elf-check,1. I am not sure, but I think Bob _ come to see me today. 2.Developed countries think that developing countries _ accept globalization. 3. If you need any help, I _ be the first one to give it to you. 5. All of us _ learn to be polite and should not smoke or talk loudly in a public place.,may,must,will,should,6. Lets get everything ready now. Our guests _ come at any time from now on. 7. Look, the light is on. Bob _ be in the room now. 8. I hope John _ come tomorrow. I have something i