易混点 1:must和have to 1) 两词都是'必须'的意思, have to表示客观的需要; must 表示说话人主观上的必要。My brother was very ill, so I had to call the doctor in the middle of the night. He said that they must work hard.2) have to有人称、数、时态的变化, 而must只有一种形式。He had to look after his sister yesterday.3) 否定结构中: don't have to表示"不必", mustn't表示"禁止"。You don't have to tell him about it. You mustn't tell him about it. 练习:1. 用mustn't 或don't/doesn't have to 完成下列句子1) I don't want anyone to know. Youtell anyone.2) I can stay in bed tomorrow because Igo to work.3) There's a lift in the building, so weclimb the stairs.4) Youforget what I told you. It's very important.5) Yoube a good player to enjoy a game of tennis.6) Don't make so much noise. Wewake the baby.答案:mustn'tdon'thave todon't have tomustn't don't have tomustn't2. Multiple Choices1. —Dad, must we wait until the light becomes green? —Yes, I'm afraid we______ .That's the traffic rule.A. can B. may C. have to D. need2.—Li Lei, hurry up! The bus is coming.—Oh, no. We ______ cross the street until the traffic lights turn green.A. mustn’t B. may not C. needn’t D. have to3. Excuse me, sir. You ______ open the door before the train stops.A. mustn'tB. needn’tC. may notD. don’t have to4. —_____I finish my homework now?—No, you_____. Your work is over today.A. Can't; must B. Must; don't have toC. May; couldn't D. Couldn't; could5. —Honey, how are you feeling now?—I am much better, Mum. So you ________ take me to see the doctor.A. can't B. mustn't C. needn't D. couldn’t6. It’s getting dark. I _____ go home now.A. can B. would C. have toD. need答案:1-6 C AABC C易混点2:can和could1) 用在疑问句中表示征求对方意见时,could比can更加委婉礼貌。Could I borrow your dictionary?Can I borrow your dictionary? 2) 用在过去时句子中只能用couldI couldn’t swim well when I was a kid but now I am a good swimmer.At the age of ten, I could remember things very quickly.练习:1. --Could I borrow your dictionary?--Of course you ____________.A. can B. must C. should D. could2. --Listen! Is Tom singing in the classroom?--No. It ________be Tom. He has gone to Paris.A. may not B. needn't C. can't D. mustn’t3. Finish your homework first, then you’ll _______ watch TV for an hour.A. can B. be able to C. able D could4. —_________ I help you, sir? —Yes. I want a T-shirt.A. Can B. Should C. Must D. Would5. —Can we run across the road now?—No, we. We have to wait until the light turns green.A. needn't B. mustn't C. couldn't D. shouldn't6. —Hello, Lisa. What's the matter?—I ______find my mobile phone. _______ you seen it?A. couldn't; DidB. can't; Have C. need ; Had D. must; Are7. —Can I hang out with my friends tonight, Mum?—Of course, but you ______ be home by 8:00 o’clock.A. can B. must C. may D. might8. Hurry up,or you ____catch the train.A. can’t B. needn’t C. mustn't D. shouldn’t答案:1-5 ADBAD 6-8 BBA易混点 3: need1) 基本用法need sth.need to do sth.I don’t need any drinks because I have had enough.You needn’t wash your car. It’s going to rain soon.=You don’t need to wash your car. It’s going to rain soon.练习:1. ―Must I return the book this week?― No, you. You canit for 20 days.A. mustn’t, keep B. needn’t, borrow C. needn’t, keepD. mustn’t, borrow2. You_________ worry about your mother. She will get well soon.A. needn’t B. don’t need C. haven’t to D. need3. You_________ return the library book today. You can keep it till next month.A. can’t B. mustn’t C. needn’t D. may not4. We ___________ to come to school yesterday morning.A. need not B. didn't need C. don’t need D. need to5. —Would you like to go swimming with me this afternoon?—I’d love to. But I’m afraid I_________. I have too much work to do.A. can’t B. mustn’t C. needn’t D. may not6. —Must I finish exercise now?—No, you_________. You_________ do it after school.A. needn’t; may B. mustn’t; mayC. needn’t; mustn’t D. mustn’t; must7. —Peter doesn’t mind lending you his camera.—He_________. I’ve already borrowed one.A. needn’t B. can’t C. mustn’t D. shouldn’t8. We __________ any drink. You’d better buy some fruit and vegetables.A. needn’t B. don’t need toC. don’t needD. not need答案:1-5 CACBA 6-8 AAC易混点4: shall和should1) shall用于句型 “Shall I/we do…?”Shall we get together and have a party tonight?Shall I tell you how to do it?2) should用来表示建议、责任、义务时,可译为“应该,应当”,此时可用ought to替换。We should try our best to help each other.=We ought to try our best to help each other.练习:选择填空。1. He eat so greedily.A. shouldn’t to B. ought to not C. ought notD. oughtn't to2. Let’s play table tennis, ?A. will we B. shall we C. shan’t weD. will you.3. Please erase the words and phrases from the blackboard after class, ?A. can you B. will you C. do you D. don’t you4. — you turning down the radio a bit?-Not at all.A. Would... mind B. Would…like C. Will…youD. Had... better5. --- we have a word with Susan?---Yes, we talk to him.A. Shall...shall B. Shall…should C. Should…shall D. Should... should6. Schools _________allow students at least one hour a day for sports.A. would B. might C. should D. could7. — you to have some pudding?—Yes, please.A. Had. . . better B. Ought.../ C. Would…like D. Would…mind8. —Shall I tell Michael about the news?—No, you . He’s already known it.A. can’tB. mustn’t C. needn’tD. don’t答案:1-5 DBBAB 6-8 CCC 易混点5: had better和would rather1) “had better+动词原形(do)” 意为“最好做……”,否定句式为had better not do sth.We’d better leave now as it’s getting dark outside.You’d better not have more sweet food or you will become even heavier.2) “would rather+动词原形(do)” 意为“宁可,宁愿”,否定句式为would rather not do sth.I would rather stay at home on a rainy day.They would rather not say anything else.1. --Bob, may I ________your MP4?--Sure. But you'd better not _________it to others.A. lend; lend B. lend; borrow C. borrow; borrow D. borrow; lend2. --What about playing football this afternoon, Sam?--I would rather _______ at home than football. It's too hot outside.A. stay; playing B. stay; playC. to stay; to play D. to stay; playing3. It is said that nowadays young people would rather_______ their friends for advice.A. askedB. askC. to askD. asking 4. We’d better _______ on the grass.A. to step B. step C. don’t step D. not step5. At present, lots of people would rather in the country because there is pollution in the city.A. live; moreB. to live; lessC. live; lessD. to live; more6. I __________play computer games than news reports.A. prefers to B. like to C. would rather D. had better7. It seems that it is going to rain. You’d better_________ the windows open when you leave the house.A. not leave B. leave C. not to leave D. to leave8. He __________ get his watch repaired. There is something wrong with it.A. have to B. has to C. had better to D. has better答案:1-5 BBBDC 6-8 CAB情态动词相关的提问与回答1) may提问—May I come in? —Yes, please. —May I borrow your bike? —Certainly.—May I take this book out of the reading-room?—No, you can’t /mustn’t.2) must提问3) —MustI do my homework now?—Yes, you must/have to.—No, you needn’t./don’t have to.4) can/could提问—Can/Could I use your computer? —Yes, you can.—No, you can’t./I’m afraid not.5) need提问 —Need I finish it now? —Yes, you must.—No, you needn't.练习:1. —_________ you tell me the way to the Beijing Normal University?—Certainly.A. Could B. Must C. Need D. Shall2. —Do I have to come back tomorrow?—Yes, you_________.A. can B. may C. must D. should3. There is somebody at the door. _________ I go and see who it is?A. Shall B. Must C. Will D. Would4. Must I water the flowers today?—________. It’s going to rain.A. No, you don’t have toB. No, you can’tC. No, you may not.D. Yes, you must5. —May I watch TV for a while?—No, you_________. You have to finish your homework first.A. shouldn’t B. needn’t C. mustn’t D. won’t6. —Must I finish exercise now?—No, you_________. You_________ do it after school.A. needn’t; may B. mustn’t; mayC. needn’t; mustn’t D. mustn’t; must7. —_________ I swim in that lake?—No, you_________. It’s dangerous to swim there.A. Must; can’t B. Can; may notC. Shall; don’t D. May; mustn’t8. —_________ you swim?—Yes, but I’m not a good swimmer.A. Can B. May C. Need D. Must9. —Don’t forget to post this letter for me, please.—No, I_________.A. don’t B. won’t C. mustn’t D. can’t10. _________ I take some photos in the hall?—No, you_________.A. Can; needn’t B. Must; mustn’tC. Could; won’t D. May; mustn’t答案:1-5 ACAAC 6-10 ABABD情态动词表猜测用法1) 肯定猜测:must (一定)>may (可能)>mightThey look almost the same. They must be twins.It’s 12:30 now. He must be there by now.This may be true but no one can say for sure.We might go abroad sometime next year but it hasn’t been decided.2) 否定猜测:can’t (不可能)>may not (可能不)>might notHe can’t be in the office because the light is off.They can’t be hungry as they had a big cake only half an hour ago.练习:1. She________ be here. I saw her come in.A. can B. may C. should D. must2. Go and ask Mr. Smith. He________ know her telephone number.A. can B. may C. need D. dare3. He________ be at home, because the light in his room is on.A. must B. can C. should D. might4. —It nearly took me an hour to walk here.—Have a drink, then. You________ be thirsty.A. should B. can C. will D. must5. John________ go there with us tonight, but he isn’t very sure about it.A. must B. can C. will D. may6. After such a long journey, they________ be very tired now.A. can B. must C. will D. need7. —The food must be good.—No, it________ be good.A. must not B. needn’t C. wouldn’t D. can’t8. —Look! The man at the gate________ be our headmaster. He is standing there every morning.—No, it________ be him. He is holding a meeting in the office now.A. must; can’t B. must; mustn’tC. can’t; can’t D. can’t; mustn’t9. —Is that your best friend Simon?—No, it________ be him. He flew to Hong Kong yesterday.A. mustn’t B. may not C. can’t D. needn’t10. —Who’s that boy reading in the garden? Is it David?—It________ be David. I saw him in the classroom just now.A. must B. can’t C. may D. shouldn’t11. —Will you answer the telephone? It________ be your mother.—Sorry, I________. I’m busy.A. can; mustn’t B. will; can’t C. may; can’t D. need; will12. I’m sure this book________ Li Lei’s, because there is his name on it.A. can’t be B. may be C. might be D. must be13. Four hundred dollars for a pair of shoes, you________ be joking!A. may B. can C. need D. must14. —What’s the matter with you? You look so tired.—Last night I________ sleep well.A. needn’t B. wouldn’t C. mustn’t D. couldn’t15. He said he________ write the article well without help.A. can B. could C. may D. must答案:1-5 DBADD 6-10 BDACB 11-15 CADDB当堂检测Multiple Choices1. —Mary, ________ you speak Chinese?—Yes, only a little.A. must B. need C. may D. can 2. —May I park my car here, Sir? —________. You may park it over thereA. Yes, you may B. Yes, you can C. No, you needn't D. No, you mustn't 3. —Let's go to the supermarket by taxi.—We________ takes a taxi. It is not far from here.A. can't B. needn't C. couldn't D. mustn't 4. —Jill looks so painful, there________ be something wrong with her.—Oh dear. We'd better take her to the nearest hospital at once.A. can B. should C. would D. must 5. Schools________ allow students at least one hour a day for sports.A. would B. might C. should D. could 6. —Look at the boy running on the ground. Is it Davis?—It________ be him. I saw him go to the teacher's office just now.A. must B. can't C. could D. might 7. You________ be tired after working for eight hours without a rest.A. can B. may C. must D. need 8. —Could I go to the movie this weekend, Dad?—Yes, you________. But you have to come back before nine.A. shall B. must C. need D. can 9. —Must I park my car behind the building?—No, you________. You________ park it here.A. mustn't; may B. may not; mustC. don't have to; may D. shouldn't; must 10. — Will you please stay here for the party ?— Sorry, I________. I’ll have to go to an important meeting.A. mustn't B. needn't C. can't D. won't 11. This kind of food________ cool, clean and dry according to the instruction.A. should be carried B. must be putC. should be placed D. must be kept 12. You________ play with fire, Tom. It's dangerous.A. needn't B. may not C. mustn't D. wouldn't 13. Alice has been in China for several years. She ________ be a big girl now.A. need B. must C. can D. may 14. —What did your PE teacher say about your high jump at the sports meeting?—He said that I________ better.A. can do B. am C. will do D. could do 15. —________I come back before 11:00? —No, you________. But you________ be back later than lunch -time.A. Must, needn't, can't B. Can, can't, mayC. Need, mustn't, must D. May, needn't, can't 16. —Can you stay here for dinner?—Sorry, I________. I have something important to do.A. don't B. didn't C. needn't D. can't 17. —I was told to be here before eight .—Oh, you________. I'm sorry for not telling you that we have changed the plan.A. must B. can't C. may D. needn't 18. —Can you play with a yo - yo , Jim ? —Yes, I _____. It's easy.A. must B. can C. need D. may 19. You ___________ finish your homework before dinner.A. needn't B. don't need C. needn't to D. not need to20. —Who is the man over there? Is it Mr Li?—No, it ________be him. Mr. Li is much taller. A. mustn't B. may not C. can't D. needn’t21. —Where is Jack, please?He________ be in the reading room. A. can B. need C. would D. must22. —Must I leave right now?—No, you________. A. may not B. can't C. mustn’t D. needn’t23. Your mother is sleeping. You'd better __________.A . not wake up her B. not to wake up her C. not wakeher up D. not to wake her up24. You'd better go and ask Mr. Yang. He ___________ know how to search the Internet.A. can B. may C. would D. could25. —It'snearly six p.m, will you have supper here? —Sorry, ________. I have many things to do. A. I mustn't B. I can't C. I needn't D. I don’t答案:1-5DCBDC 6-10 BCDAC 11-15 DCBDA 16-20 DDBAC 21-25 DDCBB强化练习Choose the best answer1. You _______ to tell him the news. It will make him sad. A. needn’t B. shouldn’t C. couldn’t D. don’t need2. –Must I do all the housework, Mum? --No, you _____. Just clean your bedroom. A. mustn’t B. shouldn’t C. needn’t D. can’t3. Jack, you ______ ask a woman her age in England. It’s impolite. A. needn’t B. don’t have to C. ought to D. shouldn’t4. We ______ hurry all the way to the airport, the flight was cancelled because of the foggy weather. A. mustn’t B. couldn’t C. needn’t D. shouldn’t5. To our surprise, we enjoy a half month holiday in January, 2012. A. shouldB. canC. mustD. need6. Can you speak louder, please? Ihear you clearly. A. mustn'tB. shouldn'tC. needn'tD. can't7. All the parcels will be delivered to your home in two days. Youworry too much about it. A. mustn't B. needn't C. can't D. shouldn't8. It doesn’t look like rain, so you _______bring your umbrella with you. A. mustn’t B. can’t C. needn’t D. may not9. Childrenbe very careful when they go across the busy street. A. shouldn'tB. needn'tC. mustD. may10. I looked everywhere for the book, but I ______find it. A. mustn't B. needn't C. may not D. couldn't11. Believe it or not, it's said that people born in the year of the rat _______ become excellent writers.A. should B. can C. must D. need12. — Must I finish my homework before I go to play basketball? —Yes, you. A. needn'tB. can'tC. mustD. may13. You tell him the good news because he has already known it. A. needn’t B. may not C. mustn’t D. can’t14. —Shall I tell Mike about it?—No, you. He's already known it. A. needn'tB. can'tC. mustD. may15. — Can I take these magazines home?— Yes, you ________ , but please return them in two days. A. mustB. mayC. shouldD. need16. —Must I wash these plates?—No, you. The machine can do it. A. mustn'tB. can'tC. may notD. needn't17. Christy has had three jobs since college, but she stilldecide what she wants to do. A. needn'tB. can'tC. mustn'tD. shouldn't18. My parents often tell me we ____ care for small creatures. A. can B. should C. mustn’t D. needn’t答案:1-5 DCDCA 6-10 DBCCD 11-15 BAAAB 16-18 DBB