八年级上语法-情态动词.doc

如果你努力学习， 你就会成功的。 If you work hard, and you will succeed.课本重点知识 八年级上 编号：句子成句情态动词: 情态动词无_和_的变化；不能_使用，必须与其后的动词原形构成_。一、 can, (过去式_)1) 表示_（体力、知识、技能）。他能搬起这个重箱子。_（体力） 玛丽会讲三门语言。_（知识）你会滑冰吗？_（技能）2) 表示请求、允许和许可 现在我可以走了吗？ _? 肯定回答： Yes,_. 否定回答：No, _.此时可与_互换。在疑问句中还可用could,代替，表示语气更委婉，不能用于肯定句和答语中。如：我明天可以来看你吗？Could I come to see you tomorrow? - Yes, you can. ( No, you cant. ) 否定式 cant在口语中代替mustnt时,表示禁止或不准。例如:You cant play football in the street.不准在马路上踢足球。3) 表示可能性(表示主观可能)， 常用语_ 句和_句， 在肯定句中用may。 Can it be true？ Can she be there？ It cant be possible. 4) 表示推测 cant 在否定句中表示_的推测。 如：我很了解他，这事不可能是他做的。 I know him very well. He _ it.二、 may 1) 表示请求和允许（用于正式场合）。否定回答可用_或_，表示“不可以，禁止”。 - May I smoke in this room? - No, you _. - May I take this book out of the room? - Yes, you can. (No, you cant / _. ) 用May I.？征徇对方许可时比较_和客气，而口语中常用Can I.？ 2) 表可能 (指客观给予主语的可能)，表示可以做或可能发生的事，一般不用于疑问句。 He may be very busy now. They may not be there. He may come, or he may not. 你妈妈可能不知道真相。Your mother _ _ know the truth. 注意：may在_陈述句中， 表示_ 可能和_ 可能，用于对人或物一时_的估计， 也可用于对人或物_、 _的估计；而表示主观可能的_, 在肯定陈述句中，指人或物_ 或倾向、经常态势，译为“有可能，有时会” 在疑问句和否定句中，can可用于对一时_ 的估计。 如：It may rain this afternoon. (不能用_ ) He may be swimming in the river now. (不能用_) He can be very friendly sometimes. (可以用_) This information can be useful. (可以用_) Can he be swimming in the river now? (不能用_) He cant be swimming in the river now. (不能用_) 3）用于祈使句，表示祝愿。 祝你成功！May you succeed! 祝你生活幸福！_三、 must, have to 1) 表示必须、必要。 如：你必须马上来。You must come at once. 在回答must引出的问句时，如果是否定回答，不能用_（禁止，不准），而用_或 dont have to（不必）。mustnt 表示禁止，指说话人强有力的命令会劝告，可译为“不准， 不可， 一定不要”。 如： Must we hand in our exercise books today? 可定回答：Yes, you must. 否定回答：No, you neednt. /_. You mustnt leave us. _ 2) must是说话人的_， 而have to则强调_需要。Must只有一般现在时， have to 有更多的时态形式。 如: 我必须先完成作业。I _. 我妈妈生病了，我必须要照顾她。My mother is ill, so I _look after her3) 表示推测, must 用于肯定句中， 表示有把握的推测。 如：你是他的好朋友，你肯定知道他最喜欢的运动。 You are his good friend. You _ know what sports he likes best. 练习 I. 单向选择 1. If he started at 9 0clock, he_ be there by now.A. need B. has to C. may not D. must 2. There is enough time. You_.A. mustnt hurry B. must hurry C. neednt hurry D. cant hurry 3. _I go back before lunch?No, you_.A. Need.must B. Do.need to C. Must.neednt D. May . must4. “_ he be watching TV now?”Yes, he_ be watching TV now?No, he _ be watching TV now.A. Must, can, mustnt B. Can ,must, cant C. Can, can, mustnt D. May, must, neednt5. I think Helen is at home.No, she _ be at home, for I saw her five minutes ago.A. mustnt B. neednt C. cant D. have not6. Could I borrow your dictionary?Yes, of course you_.A. might B. will C. can D. should7. May I stop here?No, you _.A. mustnt B. might not C. neednt D. wont8. Its still early, you_.A. mustnt hurry B. wouldnt hurry C. may not hurry D. dont have to hurry9. Would you come and join them?I wish I _. But I am busy at this moment.A. cant B. couldnt C. could D. can10. Must we come tomorrow?A. No, you cant B. No, you neednt C. No, you mustnt D. No, you may not11. I give you an answer tomorrow.A. must B. will C. may D. shall12. He didnt do well in the exam. He _ hard at his lessons.A. must work B. have to work C. may work D. cant work13.This pen looks like mine, but it isnt. Whose it _be?A. must B. can C. may D. might14. I wish to go home now, _I?A. may B. cant C. must D. do15. The taxi_ only have six people. It is full. You _take the next one.A. may.may B. can.may C. may.can D. must.can 16. He _ be working now. A. can B. mustnt C. could D. may 17. Anybody _ get ill. A. can B. cant C. may D. may not. 18. _ you be happy! A. Can B. Must C. Need D. May 19. They