must,can,may表示“推测”的用法.ppt

must,can,maymust,can,may表示表示““推推测测””的用法的用法一、对现在的推测一、对现在的推测（一）肯定推测：（一）肯定推测：must be... 一定是一定是...eg: You must be hungry after a long walk.        他们一定正在等我们让我们快点他们一定正在等我们让我们快点eg: They must be waiting for us. Let’s hurry up. （二）否定推测：（二）否定推测：can't be... 不可能是不可能是...eg: He wears glasses all the time, his eyesight can’t be good.      你不可能饿了，你刚刚吃过晚饭你不可能饿了，你刚刚吃过晚饭eg: You can’t be hungry, you have just had  dinner. （三）不确定推测：（三）不确定推测：may be... 可能可能(不不)是是...eg: The news may be true, I'm not sure.       她现在可能正在和她的同学们玩。

她现在可能正在和她的同学们玩eg: At the moment she may be playing with her classmates. 二、对过去的推测二、对过去的推测（一）肯定推测：（一）肯定推测：must have done... 一定做过一定做过...eg: You must have left your bag in the theatre.        昨天肯定下过雨了，地面是湿的昨天肯定下过雨了，地面是湿的eg: It must have rained last night, the ground is wet.（二）否定推测：（二）否定推测：can't have done... 不可能做过不可能做过...eg: He doesn't know that book at all, he can’t have read it very carefully.      他不可能杀了人，因为他那时和我在一起他不可能杀了人，因为他那时和我在一起eg: He can't have killed the man, because he was with me at that time.（三）不确定推测：（三）不确定推测：may have done... 可能做过可能做过...eg: He may have arrived at school. He is the early bird.       Anna昨天可能见过昨天可能见过Tom。

eg: Anna may have seen Tom yesterday. 从A、B、C、D四个选项中，选出最佳选项1. Jenny ___ with him at that time, for I was having dinner with her in my home. A. can’t have been B. mustn’t have been C. must have been D. may have been2. It is cold in the room. They ___ have turned off the heating. A. must B. ought to C. should D. could3. — Someone is knocking at the door. — It ______ be our neighbour. A. may B. can't C. must D. shouldAＡＡA4. I didn’t hear the phone. I ____ asleep. A. must be B. must have been C. should be D. should have been5. Johnson ____ be a policeman. He is much too short. A. may B. mustn’t C. should D. can’t6. — My friend ______ a thief. I believe her. A. can't have been B. can't be C. musn't be D. may be7. — Who told you the news? — I don’t remember clearly. It ___ Mary. — It ___ Mary. She doesn’t know it. A. may have been; can’t be B. can be; mustn’t be C. must have been; can’t have been D. may have been; may not beBBDA 结束语结束语谢谢大家聆听！！！谢谢大家聆听！！！6。