情态动词[ModalVerbs].pptVIP

情态动词（Modal Verbs);;一、表示有把握的程度情态动词可以表达对于某一事实或事件有把握的各种不同程度。;a完全有把握(肯定的或否定的）;3. must只用于肯定句中： He decided Franklin must be suffering from a bad cold. 4. can’t和couldn’t表示现在或将来不可能， couldn’t用于间接引语中，表示过去不可能： That can’t be Mr. Smith—he’s in New York. I knew it couldn’t be Mr. Smith. He couldn’t be at home. 5. would, wouldn’t 用于间接引语中，表示过 去可能或不可能： I told you wouldn’t be ready in time. ;1. should, shouldn’t, ought to, oughtn’t to, may well (很有可能）, may, may not （可能、可能不） : She should/ought to be here soon. It shouldn’t/oughtn’t to be difficult for you to work out the problem. 3. We may be buying a new flat. 4. The list may not be complete. 5. “I think it’s going to rain.” “You may well be right—the sky is really black.;C可能性小;d在理论上可能或现实可能性;2.表示某事将会实际发生，或真实情况的现实可能性通常用may, might或could: 1)---I think Labour are going to win. ---You may be right. 2)---Where is Emma? ---I don’t know. She may be out shopping. 3) Peter might call. If he does, ask him to ring later. 4) She didn’t say hello. She may not have recognized you. 5) ---Where’s Sarah? ---She may/ might/ could be at Joe’s place. ;e在条件句中表示有把握或可能;询问可能性;“could, might, ought to, should, would和needn’t +have +过分的用法;; 的 特点 1）有特定的词义 2）没有人称和数的变化 3）其后加动词原形(do), have done ,be doing. ;　; 2。表示能力: can, could, be able to *be able to 能用于各种时态。 can / could 只能表示现在或过去的能力。 *was / were able to : “设法做成某事” 相当于 managed to do sth. succeeded in doing sth.。 Eg.Though they were trapped in the big fire, they _________escape. ;4。注意对need问句的回答: --Need I finish the work today? --Yes, ________________. No, ________________. No, ________________.; --Shall I tell John about it? --No, you __________. --Must we do it now? --No, you __________. ;;2. can (用于疑问句中）， can’t, could, may, might, should, ought to, will, must + have + 过分可以表示对过去发生的事情作出推断： Where