情态动词用法总结讲解课件.ppt

情态动词 + have done 这是历年高考热点之一， 可表示“推测、责备、怀疑” 等多种意义。 一、表示对过去事情的推测或估计 1. must have done “过去肯定已经做了某事” eg: The ground is rather wet, so it must have rained last night. 2. may/might have done “可能/大概已经做了某事” eg: Tom may have gone to shanghai, but I still not sure about it. 3. can’t/couldn’t have done “不可能已经做了某事” eg: The ground is very dry, so it can’t have rained last night 注：在疑问句中 can/could 表示对过去情况的疑问性 推测，“可能已经…了吗？” eg: Someone must have broken into our bedroom, Who could have done it? 二、表示对过去所发生事情的遗憾或责备 1. should/ought to have done “过去本应该做而没做” eg: I really regretted wasting the hours when I should have studied hard, but it was too late. 2. shouldn’t/oughtn’t to have done “过去本不应该做的事却做了” eg: I’m very sorry for the words I shouldn’t have said to you at that moment. 3. could/might have done “本来能够做的事却没做” eg: He could have worked out the problem. 4. needn’t have done “原本不必做的事却做了” eg: Your home is not far from your school, so you needn’t have left in such a hurry. 5. Would like to have done “本打算做某事但没做成” eg: I would like to have come to visit you, but I had to look after my sick mother at home. * 情态动词的语法特征 2) 情态动词不能单独做谓语, 后面只能接动词原形，ought to和have to除外，。 3) 情态动词没有人称, 数的变化, 但有些情态动词, 如can、will、have to、may等有过去式。 1）情态动词表说话人的某种感情或语气，对某一动作或状态的某种态度。 1) Some of us can use the computer now, but we couldn’t last year. 2) Can she be in the computer center? 3) I though what he said could not be true. 4) Can/Could I use your dictionary? 5) Could you lend me a hand? 1.表能力,意为“能，能够”，can指现在，could指过去。 3. 表示“请求” “允许”(表请求时，口语中常用 could 代替 can 使语气更委婉，回答时用can) 2. 表示推测，意为“可能”“或许”，用于疑问句或否定句，can’t和couldn’t意为“不可能”。 1. can 与could 4. can 用于疑问句或否定句中时，表惊异、 不相信等，意思是“可能、能够”。 6) How can you believe such a liar like him? 5. can’t/ couldn’t have done 表示对过去情况的否定推测,意为“过去不可能做过某事” 7) Susan can’t have written a report like this. 8) She can’t have