Modal Verbs ()must, may, should, will, have toStudying the Rule1) 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?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.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. 1. must與與have to的區(qū)別的區(qū)別have to比較強調(diào)客觀需要比較強調(diào)客觀需要, must著重說明主觀看法。另著重說明主觀看法。另外外have to能用于更多時態(tài)能用于更多時態(tài), 比較下面的句子：比較下面的句子：We had to be there at 10:00. 有時兩者都可以用有時兩者都可以用, 意思差別不大。意思差別不大。e. g. We must/have to leave now. must在表示說話人對事物的推測時在表示說話人對事物的推測時候要注意它比候要注意它比may肯定得多肯定得多, 相當于相當于漢語的漢語的“一定一定”或或“準是準是”。(只有只有在肯定句中能這樣用。在肯定句中能這樣用。) This must be your room 在回答由在回答由must引起的問題時引起的問題時, 如如果是否定的答復，不能用果是否定的答復，不能用mustnt, 而需要用而需要用neednt或或dont have to, 因為因為mustnt是是“一定不要一定不要”的意思的意思。2. may的用法的用法: a. 表示表示“允許允許”或或“請請求求”。 e. g. May I come in？ 在使用這一用法時需注意在使用這一用法時需注意: may表表示示“允許允許”的否定形式是的否定形式是must not, 意思是意思是“不應(yīng)該不應(yīng)該” “不許可不許可”。e. g.May I take this book out of the reading-room？No, you mustnt b. 表示說話人的猜測，認為某一表示說話人的猜測，認為某一事情事情“或許或許”或或“可能可能”發(fā)生。發(fā)生。 e. g. He may know the answer c. may用在感嘆句中可表示祝愿、用在感嘆句中可表示祝愿、愿望。愿望。 e. g. May you succeed(祝你成功。祝你成功。) May you have a pleasant journey(一路平安。一路平安。) 3. should是是shall的過去式，它可以用的過去式，它可以用于過去時態(tài)中，但更多的是用作于過去時態(tài)中，但更多的是用作情態(tài)動詞，意思是情態(tài)動詞，意思是“應(yīng)當；應(yīng)應(yīng)當；應(yīng)該該”，用來表示義務(wù)或責任。此，用來表示義務(wù)或責任。此時，它不再局限于和第一人稱的時，它不再局限于和第一人稱的代詞連用，而是三種人稱都能使代詞連用，而是三種人稱都能使用。例如：用。例如： You should answer my question in English. 你應(yīng)當用英語回答我的問題。你應(yīng)當用英語回答我的問題。 They shouldnt be so careless. 他們不該如此粗心。他們不該如此粗心。 Its raining hard. You should drive slowly. 雨下得很大。你開車要慢些。雨下得很大。你開車要慢些。 should還可以用在提供幫助、提出建還可以用在提供幫助、提出建議、要求、給予指示的句子中。議、要求、給予指示的句子中。例如：例如： Should I help you carry the basket? 要不要我?guī)湍闾峄@子？要不要我?guī)湍闾峄@子？ What should I do for them? 我應(yīng)當為他們做些什么？我應(yīng)當為他們做些什么？ 應(yīng)當注意的是，當應(yīng)當注意的是，當should表示上述兩表示上述兩種意思時，要重讀。種意思時，要重讀。 4. will 情態(tài)動詞情態(tài)動詞 aux. (客氣提問客氣提問)是是否愿意；否愿意；好嗎好嗎 word that you say when you ask a polite question Will you pass the salt? 請你把鹽遞給我，好嗎？請你把鹽遞給我，好嗎？ Will you please give him a message when you see him? 你見到他時捎個口信給他好嗎？你見到他時捎個口信給他好嗎？ Wont you come in and have a little tea? 要不要進來喝點茶？要不要進來喝點茶？ Will you please lend me your rubber? 請借給我你的橡皮好嗎？請借給我你的橡皮好嗎？ 表推測表推測1.must（一定）只用于肯定句中（一定）只用于肯定句中,He looks so pale. He must be ill.2.can / could用于肯定、否定、疑問句用于肯定、否定、疑問句中中,It cant be Mr. Wang . He has left here.3.may / might可用于肯定、否定句中可用于肯定、否定句中There may be some dangerous animals on the island.4.should（想必）（想必）They should be there by now.5.如果對過去發(fā)生的事情的推測如果對過去發(fā)生的事情的推測要用完成時。要用完成時。Someone must have opened the cage. The lion couldnt have escaped on its own.準是有人把籠子打開了，獅子不準是有人把籠子打開了，獅子不可能自己跑出來?？赡茏约号艹鰜怼Ｒ话阋蓡柧涞目?、否定回答一般疑問句的肯、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等過去式等過去式用在疑問句表語氣委婉時，其用在疑問句表語氣委婉時，其回答要用原形?；卮鹨迷?。 -Could you tell me whats the matter with you?-Yes, I can. Sure./ Certainly/ Of course.Finding the Rule1) Giving advice2) Saying that something is necessary3) Politely asking someone to do something4) Asking someone for permission to do something5) Saying that perhaps something will happen_476216) Saying that sth. will almost certainly happen, as long as nothing unexpected stops it7) Expressing an opinion about something that the speaker is not sure about.8) Expressing obligation(義務(wù)義務(wù)) and duties.9) Expressing need.3589_1)A: Do we have to finish this job today? B: Yes, you_.2) If it 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 RuleComplete the following sentences with may, should, must, will or have to. must should/ must may may 5) A:You 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.8)He _ stay at home because his right leg is broken.9)Listen! You really _ give this to Mary! Its very important.have to should will has to must 1) Ask your teacher for permission to leave school early tomorrow.Applying the RuleMake 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 harder.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 tomorrow. 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 wants 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.Self-check1. 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 important to tell him.9. Adults _ not be rude to children. Otherwise, they _ be rude to adults.10. I saw Mary in the bookstore a few minutes ago. She _ not be in the classroom now. may must will should will cant 1. In crowded places like airports and railway stations, you _ take care of your luggage. (2007北京卷北京卷)A. can B. may C. must D. will2. - How is your tour around the North Lake? Is it beautiful? - It _ be, but it is now heavily polluted.A. will B. would C. should D. must3. She looks very happy. She _ have passed the exam.I guess so. Its not difficult after all. (2007)A.should B. couldC. must D. might