情态动词表示推测

1、情态动词表示推测用法的比较must只用在肯定陈述句中 must+状态动原（对现must have done （对过去在情况的推测）,表示 满有把握，“一定、想 必已”情况的推测），推测有把握已经发生过事，即:“准是、想必已 The man could eat all those apples, so he must have a good digestion. She must dislike such a man. He must have arrived there already. Her eyes are red. She must have been crying long He m

2、ust be sleeping.can表推测用在否定句或疑问句中. 1 .“There's the doorbell. -Who can it be at this time of day? 2.-lt must be Terry that came to see us. -It carft be Terry. He，s now in London. Where can he have gone?他到哪儿去了 ？ He can't have gone to school. We have no school today.canJt +动词原形（对现在情况的推测）,表示不 car

3、ft have done （对过 去情况的推测），推测 某事不可能已经发生。可能.could could +动词原形（对现 在情况的推测），表示可 疑的可能性，用在否定、 疑询应肯定句审 Could I borrow your car? Could it be true?那会是 真的吗？ She couldn" t make any mistakes on this matter.关于这个问题她 不应该犯错 The weather in Tibet could be cold now. could have donecouldn't have done （对过去情况的推测），

4、推测某事可能已经发生或某事本来可能发生，但实际上蠶烈否定式表示不 We could have walked there; it was so near. He couldrft have said such a thing.他应该不 会说出这种话的may may +动词原形may not +动词原形（对现在情况的推测）， 其肯定式表示“可能”； 否定式表示“可能不” He may be right; I may not be right.（may表推测不用于疑问句:）那会是真的吗 Can that be true?不能说成:May that be true? may have done （对过

5、去情况的推测）,对已经发生的事进行推测，意为 “可能已”;否定式表示“可能还不” She isn't here by now; she may have missed her train He may not have known it.他可能还不知 道那件事mightmight +动词原形（对现在情况的推测），可能, might have done （对过去情况的推测），但更但不及may肯定；其否定 式也不及mayrVt语气强 He might not be there today.（今天他可能不在 那儿）没把握；表示某事本应 该发生却未发生，有责 备意味 Might he have

6、 missed the train?（他没赶上车 吗？）should ought to should +动词原形（对 现在情况的推测）,只用 右肯亢旬中，爰示“该” Children should be taught to speak the truth should have done (对过去情况的推测），表示“原本该，但未做到”， 含有较强责备口气，后 者更强 You should have told me earlier. (But you told late.)shouldrTtought rTt to shouldn't have done (对过去情况的推 测)，表示“原

7、本不该，但却做了”，含 有意味 She shouldn't have come here(But she came.)needrft needrTt have done （对过去情况的推 测），只用在否定句，表示“原本不 必做，但做了” ,即：做了不必做的 事 There was plenty of time then. We needrft have hurried1.2.4.5.mustcancouldmaymight4情态动词+进行时（对现在活动的推测）或完成情态动词之间相互排斥，故不能同时使用；情态动词的过去式有时并不表示“过去”，而只 起"使语气委婉”的作用；情态动

8、词表“推测”时，must语气最强，依推测 的“可能性”从大到小其顺序一般是：进行时（对一直在进行的活动的推测）的用法:6. -What can/could he be doing now?7. -He may/might be watering the flowers.8.9.He can't be sleeping.She must have been writing the paper for days.（她肯定几天来一直在写论文。）5在反意问句中，表推测的情态动词不出现在简短问句部分，而其后的动词使用为：句中有 过去时间状语的，问句部分用过去时，否则, 用现在完成时。例如：He must have been there yesterday, wasn'