七年级下册(1)情态动词常见的情态动词:can, could, may, might, must, should, need, had better have to等含义:表示说话人对所述动作的看法,如需要、可能、意愿或怀疑等。
1.用法特点:⑴它们必须与其他动词连用,即:肯定:情态动词+动词原形:He can swim.否定:情态动词+not+动词原形:He can not(can’t)swim.一般疑问句:把情态动词提前:Can he swim?Yes,he can./No,he can’t.表示说话人对所述动作的看法,如需要、可能、意愿或怀疑等。
⑵情态动词没有人称和数的变化,即第三人称单数不加-s,有些情态动词有时态的变化⑶在意义上,情态动词具有“多义性”。
例:can既可表示能力,又可表示可能、允许等意义。
2.各情态动词的用法(1)can:表能力,“能,会”;表可能,猜测,通常用于否定句和疑问句中,This boat can’t be hers, hers is black.(2)could:表can的过去式;表请求允许,比can更委婉地提出请求。
(3)May: 表猜测,“可能”(只能用于肯定句,否定句用can’t)表征求同意,May I come in?(4)Might: may的过去式;might比may更加委婉。
(5)Must: 表义务的“必须”表事情的必要性和重要性。
You must take care of your parents. 表推测的“一定,准是”(只有肯定猜测,否定猜测用can’t)The lady must be a doctor.(6)Should: 表义务或责任“应该”。
(7)Need: 表必要性。
(8)Would: will的过去式;表示意愿或用于第二人称的疑问句中,表礼貌委婉的请求,比can更委婉。
(9)Had better: 最好,(had better not)3.易混的情态动词(1)Can/ could 与be able to: 表“能力”时can只有现在和过去时两种时态,其余时态用be able to,can指与生俱来的能力,be able to后天形成的能力。
(2)含有情态动词的疑问句的回答:1).对may引出的问句,可以有下列回答方式:Yes,you may. Yes, of course.Yes, certainly.Sure .No, you can’t.2).对must引出的疑问句,回答方式为:Yes, …must.No,…don’t(doesn’t) have to./needn’t3).could在疑问句中,表示委婉的语气,此时could没有过去式的意思。
如:Could you help me?你能帮我个忙吗?—Could I use your pen?我能用一下你的钢笔吗?—Yes, you can.可以。
(注意回答)4).would you…的回答方式有以下几种:Yes, I will. (No, I won’t.)Sure . (I’m sorry , I can’t.)All right/ OK/ With pleasure.Certainly. (No, thank you .)Yes, please.(3)Must 的否定形式:mustn’t “不许,禁止”(must表推测时无否定形式,否定猜测用can’t)(4)Need:作实义动词时,后接名词、动名词、动词不定式She doesn’t need to take any medicine.作情态动词时后接动词原形。
She need take some medicine.一、用can, may, must, need, have to, had better的适当形式填空:1. You ________________ return the library book on time.2. I ______________ (not) find the way to the hospital. _______________ youshow me the way?3. —________________ I finish the work right now?— No, you ________________ (not). You ____________ do it later.4. He said he ________________ (not) come tonight.5. Her mother was ill. She ________________ stay at home and look after her.6. It’s time for class. You ________________ stop playing football or you__________be late for class.7. We ________________ start right now, or they would get there first.8. The cloud is lifting, so it ________________ (not) be a rainy day tomorrow.二、选择填空()1.—Do we have to finish our homework this afternoon?—Yes, you ________.A. mustB. canC. mayD. need()2. —Must I be in hospital for a week,Doctor?—No,you . You can go back home tomorrow.A.mustn’tB. needn’tC. must()3. The desk is not dirty. You _______clean it.A. mustn’tB. shouldn’tC. needn’t C. can’t()4. —May I watch TV for a while?—No, you _______. You have to finish your homework first.A. shouldn’tB. needn’tC. mustn’tD. won’t()5.—Is Jessica giving us a speech this evening?—No, it ________be her. She________ to Japan.A. mustn’t; has goneB. mustn’t ;has beenC. can’t ;has goneD.can’t ;has been()6. I t’s the library! So you________ know shouting is not allowed here.A. canB. mustC. needD. may()7. Boys and girls, don’t forget your report . It ______ today.A. can’t finishB. can’t be finishedC. should finishD. should befinished()8.—Mr Smith must have been to your home this morning.—No, he ______ ,because he didn’t know my address.A. couldn’tB. can’tC. mustn’tD. may not()9. —Must I mop up the window now?—No, you________.A.needn’tB. can’tC. shouldn’tD. mustn’t()10. —Is Lucy knocking at the door?—No. It ________ be Lucy. She is in Japan now.A. needn’tB. mustC. can’t()11. —Another cup of coffee?—No, thanks. I _____ be off. Mary is waiting for me.A. canB. mayC. mustD. might()12. —I’m a little tired. Let’s go to the zoo by taxi.—We take a taxi. It’s not far from here.A. can’tB. mustn’tC. couldn’tD. needn’t()13. If the traffic light is red, you ________ cross t he road. It’s very dangerous.A. don’tB. mustn’tC. needn’tD. wouldn’t()14. —Must I finish watering the flowers now?—No, you________.A. mustB. won’tC. needn’tD. can’t()15. —I can’t give up sm oking, doctor.—For your health, I’m afraid you ________.A. mayB. canC. have toD. must()16. It is usually warm in my hometown in March, but it _______ be rather cold sometimes.A. mustB. canC. shouldD. would()17. —Our class won the English speaking contest.—Congratulations! You _______ be very proud of it.A. canB. needC. wouldD. must()18. —Excuse me, where are we going to have our class meeting?—I’m not sure. Ask our monitor, please. He know.A. canB. mayC. needD. shall()19. —____________I borrow these magazines?—Sorry, only the magazines over there can be borrowed.A. MustB. WouldC. MayD. Need()20. If the traffic light is red, you ________ cross the road. It’s dangerous.A. don’tB. needn’tC. mustn’tD. wouldn’t 【中考链接】()1.—Who is the man over there? Is it Mr. Li?— No, it ______ be him. Mr. Li is much taller.A. mustn’tB. may noC. can’tD. needn’t()2.—Must I go with them tomorrow?— No,you ______.A. mustn'tB. shouldn'tC. needn'tD. can't()3.—______ I take some photos in the hall?— No, you ______.A. Can, needn’tB. Must, mustn’tC. Could, won’tD. May, mustn’t ()4.—Dad, must I finish my homework today?—No, you ________. You may do it tomorrow.A. needn’tB. mustn’tC. don’tD. won’t ()5.—The lake is said to be dry. Is that true?—It _______.Look, some kids are swimming in it.A. must be trueB. can’t be trueC. may not be true()6.—What is your mother going to do this Saturday?—I’m not sure. She _____ go to see my grandmother.A. canB. mustC. may()7.—Susan has bought a large house with a swimming pool.—It ______ be very expensive. I never even dream about it.A. mustB. mightC. can’tD. shouldn’t ()8.—Listen! Is Professor Johnson giving a report in the hall?—No, it be him. He has gone to Japan.A. needn’tB. may notC. mustn’tD. can’t()9.—Let’s go to the West Hill Park by taxi.—Oh, it is not far away from here. We _______take a taxi.A. couldn’tB. mustn’tC. needn’tD. can’t()10.—Can you play the piano?—Yes, I _______. I often practice it on weekends.A. needn’tB. needC. can’tD. can。