M4Unit2《Sporting_events》grammar 情态动词 很好.ppt

Unit 2 Sports events Modal verbs Warming-up exercises He ____ speak English fluently. (表能力) 2. You _____ work hard to win the gold medals. (表责任/义务) 3. ______we do some exercises this morning? (表征求对方意见) 4. --- Might I watch TV after supper? ---Yes, you ________. A. may B. must C. might D. could 5. ---May I pick a flower in the garden? ---________. A. No, you need B. No, please C. No, you mustn’t D. No, you won’t must can Shall A C 一．情态动词的语法特征 情态动词表示说话人对某一动作或状态的态度，可以表示“可能”、“可以”、“需要”、“必须”或“应当”等之意。 情态动词没有人称和数的变化。 情态动词不能单独作谓语动词用，必须和不带to的不定式连用构成谓语动词。 Modal verbs: general introduction 二．情态动词的语法功能 We can use modal verbs to talk about: ability certainty permission obligation make requests make suggestions make offers give advice 能力 义务, 责任 确定 允许 提出请求 提出建议 提供帮忙 提出忠告 Modal verbs: general introduction 　 情态动词 1. can could be able to 2. shall 4. may might 三．常见情态动词的基本用法 3. must have to 7. will would 5. need dare 6. ought to should 8. 情态动词+have done 　 情态动词 can could be able to shall will may might The usage of some common modal verbs mustn’t needn’t 情态动词+have done 5. 情态动词+be doing 表示对现在发生事情推测，表现 正在进行的或可能正在进行的动作。 The boy may be playing football on the play ground. He can’t be doing his homework upstairs. must have done 过去一定做过某事 can’t have done 过去不可能做过某事 should ( ought to ) have done 过去本该做某事却没做 shouldn’t ( ought not to ) have done 过去本不该做某事却做了 5. 情态动词+have done表示对已经发生事情推测、 责怪、后悔、遗憾等。 needn’t have done 过去没有必要做某事而实际上却做了 could have done 过去本可以做某事却没做 may / might have done 过去可能已经做了某事 5. 情态动词+have done表示对已经发生事情推测、 责怪、后悔、遗憾等。 ① can表示本身所具有的能力或潜能， could是其过去式 *我认为没有你的帮助他不能解决这 个问题。 I dont think he can solve the problem without your help. *两年前Rose就能自己烧饭了。 Rose could cook meals for herself two years ago. 1. 情态动词can, could和b