情态动词must, can, need 在上一模块我们学习了情态动词may和might的用法，大家掌握了吗？本模块我们来学习must, can, need这三个情态动词的用法。 1. must意为“必须；一定要”，表示说话人的主观想法，即有必要或有义务去做某事；must的否定形式是must not(mustn’t)，意为“一定不要,不允许”。由must构成的一般疑问句的肯定回答用must，否定回答用needn’t。如： You must finish the work before 11：30 am. John, you mustn’t forget to take your English book. —Must I have dinner now? —Yes, you must. / No, you needn’t. 2. can能够表示允许，意为“许可，能够”；can的否定形式是cannot(can’t)，表示不允许，意为“不能，不能够”。由can构成的一般疑问句的肯定回答用can，否定回答用can’t。如： You can go swimming with us if you want to. You can’t play basketball after meals. —Can we read here? —Yes, you can. / No, you can’t. 3. need意为“需要”；need的否定形式是need not(needn’t), 意为“不需要，不必要”。由need构成的一般疑问句的肯定回答用must，否定回答用needn’t。如： I need a French dictionary. You needn’t take that big bag. —Need I arrive at the school gate earlier? —Yes, you must. / No, you needn’t. 【运用】从各题后所给的选项中选择可以填入空白处的最佳答案。 ( ) 1. —Must I hand in my homework now, Mr. Smith? —No, you ______. A. can’t B. shouldn’t C. wouldn’t D. needn’t （2014北京） ( ) 2. Children ______ sit in the front seat of a car. It’s too dangerous. A. need B. needn’t C. must D. mustn’t (2014 重庆) ( ) 3. —Must I water the flowers now, mum? —No, you ______. You ______ do it later. A. mustn’t, must B. mustn’t, may C. needn’t, may D. needn’t, must （2014贵州铜仁） ( ) 4. —Can I swim in the river, Grandpa? —______. It’s dangerous. A. Yes, you can B. No, you can’t C. Yes, you need D. No, you needn’t （2014江苏宿迁） ( ) 5. —Must I go to law school and be a lawyer like you, Dad? —No, you ______, son. You’re free to make your own decision. A. can’t B. mustn’t C. shouldn’t D. needn’t （2014甘肃平凉） ( ) 6. —Lingling, can I use your e-dictionary? —Sure. But you ______ return it after class. A. must B. can C. may D. would (2014 山东德州) ( ) 7. Look at the “No parking” sign. You ______ park your car here. A. should B. must C. needn’t D. mustn’t (2014 天津) ( ) 8. If you ______ smoke, please go outside. A. can B. may C. must D. might (2014 浙江杭州) 答案 1-5 DDCBD 6-8 ADC 本文来源：https://www.wddqw.com/doc/f9e1e1c2a7e9856a561252d380eb6294dc882295.html