高中英语语法——情态动词表推测用法总结及练习（无答案）

情态动词表推测用法总结（一）情态动词表推测的三种句式
能用于表推测的情态动词：must, can, could, will, would, may, might, should, ought to1.在肯定句中一般用must (一定)，may（可能），might / could（也许，或许）。
　  （1）He must/may/might know the answer to this question?　　他一定/可能/也许知道这个问题的答案。
　　（2）It is cold in the room. They must have turned off the heating.　　屋里很冷，他们肯定把暖气关了。
　　2.否定句中用can’t / couldn’t(不可能), may not/might not(可能不)。
　 （1）It can’t/couldn’t be the headmaster. He has gone to America.　　这不可能是校长，他去美国了。
　　（2）He may not/might not know the scientist.　　他也许不认识那位科学家。　　3.疑问句中用can/could (能……?)。
　　（1）Could he have finished the task?　　 他可能把任务完成了吗？
　　（2）Can he be at home now?　　 他现在能在家吗？
　　注：以上三种句式中情态动词的语气按程度都是依次递减的。might, could并非may, can的过去式，而表示语气较为委婉或可能性较小。 Couldn’t 比can’t 语气弱一些。　　
　　（二）情态动词表推测的三种时态
　　1.对将来情况的推测，用“情态动词 + 动词原形”。
　　（1）She must / may / might / could arrive before 5.　　5:00前她一定/可能/也许到。
　　（2）She must/may/might/could walk miles and miles among the hills without meeting anyone.
　    　她一定/可能/也许会在山里一连走好几英里而遇不到一个人。
　　2.对目前或一般情况的推测，用“情态动词 + be”或“情态动词 + 动词原形”。
　　（1）He can’t ( couldn’t ) / may ( might ) not be at home at this time.　　这个时候他不可能/可能不在家。　3.对正在发生动作的推测，“情态动词 +be doing” （1）He must / may / might / could be listening to the radio now. 他一定/可能/也许正在听收音机。
　　4.对过去情况的推测，用“情态动词 + have +过去分词”。
　　（1）It must / may / might / could have rained last night .The ground is wet.　　地湿了，昨晚肯定/可能/也许下雨了。 （2）The door was locked. He can ( could ) not / may ( might ) not have been at home .　门锁着，他不可能/可能不在家。
　　（3）Can / Could he have gotten the book？　　难道他找到书了吗？　　补充强调：推测的句型特点（对某一次的推测句型有两部分：语气和时态）
（1）语气部分：（以下情态动词语气由强至弱）
     肯定句：must、may、might（=could）
     否定句：can’t（=couldn’t）、mayn’t、mightn’t  
     疑问句：can、could（语气更加委婉不确定）
（2）时态部分：    be表示对现在的推测     have done表示对过去的推测     be doing表示对正在进行的推测语气部分写在前时态部分写在后，组合在一起就是推测（三）几组表推测的情态动词用法“情态动词＋完成时”是历年高考的热点，在做此类练习时，既需要掌握这一结构的基本用法，又应该仔细体会题干所提供的语言信息，准确理解语言环境和说话人的含义，尤其要注意题干中时态给予的暗示。 .must have done 表示对已经发生的事情的推测，意为“一定，想必”, 句子中表示的是一种肯定的推测。这种结构一般只用于肯定句，其否定形式是can’t （couldn’t）have done ，表示“不可能，肯定不会”。例如：
He didn’t hear the phone . He must have been asleep. 他没有听到电话响，他肯定是已经睡着了。
根据句子意思用must, might, could或can’t填空1. The white ruler______________  belong to Lucy. Hers is red.2. I can’t find my keys. They ______________ be still at home.3. The exercise book______________belong to Bob. It has his name on it.4. Jim______________ be at home. He has gone to his hometown.5. This blue shirt ______________ belong to Ken. He likes blue best.6. The schoolbag ______________ be Paul’s. There are a lot of books in it.7. The volleyball______________  belong to Alice. She plays volleyball every day.8. The classroom is clean. Someone ______________  clean it just now.9. –Is that Bob there?  –No, it ______________ be him. He has gone to Shanghai with his family10. –where is Mr. Lee?  –The light in his bedroom is still on. He __________  be there.11. I ______________ find my pencil case. I think I have lost it.12. The boy is clever. He  ______________ tell many stories when he was young.13. The man is running fast. He______________  be catching the bus.14. Li Lei has learned English for 15 years. He ______________  know the meaning  of this sentence.15. –What are you going to do this weekend ? –I’m not sure. I ______________ visit my grandparents.16. –Who is that boy in blue?   –It______________ be Tim. He is always reading English there every morning.   –It______________ be him. He is talking with Miss Liu in the classroom.17. I thought you __________ be hungry, so I have brought you some cakes.18. -Here are some earrings. The owner ______ be a boy.-Well, it _______ be a boy. The earrings ______ be a present for his mother.19.-Are you coming to Jeff’s party?   -I’m not sure. I ___________  go to the concert instead20. I have tried to call him at the office, but there is no reply. He______________ be at home.