Unit 6 语法 情态动词学案 2025-2026学年沪教版英语八年级下册

第4讲 新版沪教牛津版八下 Unit 6 语法---情态动词 Part 1 情态动词讲解 一、情态动词had better 1. had better表示“最好”，其缩写为“’d better"，表示“ 。 例1: You had better go to bed early. 2. had better否定形式为 例如: 例2: You had better not stay up late. 注意： 1. had better 后面必须跟动词原形。 2. 主语无论是第几人称，无论用什么时态，都要用had better的形式。 例3: Now you/ he/ we had better listen to the teacher. 2、 情态动词should, ought to 1. should作情态动词，表示劝告、建议，作 ；语气比 ought to要弱。 例4: You should keep your promise. 例5: You should study first aid(急救法) with the teacher. 2. ought to表示客观上有责任、有义务做某事，语气较强。其否定形式为 。 例6: You ought to drink plenty of water. 3. should , ought to 用于疑问句时, should 直接放 ,而ought则把 ought放在 ，to放在 。 例7: Should I open the window? 我应该打开窗户吗? 例8: —Ought he to go? 他应该去吗? —Yes. I think he ought to. 是的,我想他应该。 【即学即练】 (1) You _______ drive your car so fast. It’s very dangerous. A. wouldn’t B. shouldn’t C. couldn’t D. mightn’t (2) A country has dreams. We teenagers _________ also have dreams. With dreams and hard work, anything amazing can be created. A. may B. must C. should D. Might 三、复习can，may，must 等情态动词在陈述句中的用法 1. can 的用法： （1）表示能力时一般译为“ ”， 即有种能力，尤其是生来具备的能力。 例9: She can swim fast, but I can’t .  （2）表示推测，意为“ ”， 常用于 中， 此时can’t 译为“ 不可能”。  例10: --Can it be our teacher? --No, it can’t be our teacher. He is on a visit to the Great Wall. 2. could的用法： （1）can的过去式，意为“ 能、 会”，表示过去的能力。 例10: He could write poems when he was 10.  他十岁能够作诗 （2） could在疑问句中，表示 ，此时 could 没有过去式的意思。 例10:--Could you do me a favour?  --Could I use your pen?  --Yes, you can.可以。（注意回答） 3. may的用法： （1）表示请求、许可，比can 正式。 例11: May I borrow your bike?  （2）表示希望、祈求、祝愿，常可译为“祝愿”。通常是用may +主+V 。 例12: May you have a good time.  4. must的用法： (1) must 表示主观看法，意为“必须、一定”。  例13:You must stay here until I come back. (2) 其否定形式mustn’t表示“ 一定不要 ” “千万别” “禁止, 不许”。 例14:You mustn’t play with fire.   (3)对must引导的疑问句，肯定回答为must，否定回答为needn’t  或 don’t have to。 例15: --Must I finish my homework? --No, you needn’t. 5. need的用法： need 表示需要、必须，其否定形式为needn’t，意为“没有必要，不必”。  例16: You need come early. Part 随堂练习 一、单项选择 ( ) 1. Mr Wang ______ be in Nanjing now, he went to Beijing only this morning. A. mustn’t B. may not C. can’t D. needn’t ( ) 2. –Must I stay at home, Mum? --No, you ______. A. needn’t B. mustn’t C. don’t D. may not ( ) 3. –Can you go swimming with us this afternoon? --Sorry, I can’t. I _____ take care of my little sister at home because my mother is ill. A. can B. may C. would D. have to ( ) 4. –May I go to the cinema, Mum? --Certainly. But you ______ be back by 11 o’clock. A. can B. may C. must D. need ( ) 5. To make our city more beautiful, rubbish ______ into the river. A. needn’t be thrown B. mustn’t be thrown C. can’t throw D. may not throw ( ) 6. –May I go out to play basketball, Dad? --No, you ______. You must finish your homework first. A. mustn’t B. may not C. couldn’t D. needn’t ( ) 7. –Where is Jack, please ? --He _____ be in the reading room. A. can B. need C. would D. must ( ) 8. –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’t ( ) 9. These books ______ out of the reading room. You have to read them here. A. can’t take B. must be taken C. can take D. mustn’t be taken ( ) 10. –Mum, may I watch TV now? --Sure, but you ______ help me with my housework first. A. can B. may C. must D. could ( ) 11. The boy said he had to speak English in class, but he ______ speak it after class. A. could B. didn’t have to C. might D. shouldn’t ( ) 12. –Must we hand in the papers now? --No, you ______. A. can’t B. may not C. mustn’t D. needn’t ( ) 13. John ______ go there with us tonight, but he isn’t very sure about it. A. must B. can C. will D. may ( ) 14. Even the top students in our class can’t work out this problem. So it ______ be very difficult. A. can B. may C. must D. need ( ) 15. Put on more clothes. You ______ be feeling cold with only a shirt on. A. can B. could C. would D. must ( ) 16. It’s still early. You ______. A. mustn’t hurry B. wouldn’t hurry C. may not hurry D. don’t have to hurry ( ) 17. –May I stop here? --No, you ______. A. mustn’t B. might not C. needn’t D. won’t ( ) 18. A computer ______ think for itself, it must be told what to do. A. can’t B. couldn’t C. may not D. might not ( ) 19. –Could I borrow your dictionary? -- Yes, of course you _______. A. might B. will C. can D. should ( ) 20. Michael ______ be a policeman, for he’s much too short. A. needn’t B. can’t C. should D. may 二、用括号中所给单词的适当形式填空。 1. You should __________ (bring) your homework to school tomorrow. 2. You'd better __________ (go) and ask the policeman. 3. You ought to __________ ( read) loudly in the morning. 4. You'd better __________ (not take) off your coat. 5. He can __________ (write)a storybook though he is only twelve. Part 3 课后练习 一、选择题 ( ) 1. What kinds of homes will we live in the future? Nobody __________ be sure, but scientists are working out new ideas now. A. will B. may C. can D. must ( ) 2. I ______ like to know where you were born. A. shall B. should C. do D. may ( ) 3. ______ you be happy! A. Might B. Must C. Wish D. May ( ) 4. A teacher ______ do every exercise, but a student must. A. may not B. needn’t C. can’t D. mustn’t ( ) 5. The matter ______ be changed into a gas, but it _______ be heated to its boiling point. A. may; needn’t B. may; can C. mustn’t; needn’t D. can; must ( ) 6. Teachers and students ______ look coldly at you for a day or two, but there are friendly feelings in their hearts. A. must B. can C. may D. should ( ) 7. Cars and buses ______ stop when the traffic lights turn red. A. can B. need C. may D. must ( ) 8. –Do you think his story ______ true? --I don’ think so. But it sounds good. A. must be B. may be C. can be D. has to be ( ) 9. Look out! The knife is very sharp. You ______ cut your finger. A. need B. must C. should D. may ( ) 10. –How long ______ the book be kept? --For two weeks, but you ______ return it on time. A. can; may B. may; need C. can; must D. must; need ( ) 11. – May I have an apple, Mum? --Certainly. But you ______ wash your hands first. A. may B. must C. can D. need ( ) 12. –There is a lot of smoke coming out of the teaching building there. --Really? It ______ be a fire, most probably. A. can B. ought to C. may D. must ( ) 13. –Shall I tell John about the bad news? --No, you ______. I think that will make him sad. A. needn’t B. wouldn’t C. shouldn’t D. mustn’t ( ) 14. –Could I call you by your first name? --Yes, you ______. A. will B. could C. may D. might ( ) 15. –Let’s go to the cinema, shall we? -- _______. A. No, I can’t B. Yes, I will C. Yes, thank you D. No, we’d better not 二、完成句子 1. 晚餐后你应该去散散步。 You after dinner. 2. 我们应当先弄清真相。 We the truth first. 3. 杰克不应该从事教师工作。 Jack a teacher. 4. 你不应该向他挑战比赛。 You him to a game. 5. 我们应该依靠父母吗？ we our parents? 6. 你最好把黑板上那些单词抄下来。 You the words on the blackboard. 7. 他们最好能将这个短剧表演出来。 They the short play. 8. 她最好别用电话跟我保持联系。 She _______ with me by phone. 9. 你最好不要进入那个房间。 You the room. 10. 过马路时，我们最好小心为是。 We when crossing the road. 学科网（北京）股份有限公司 $