情态动词表示推测

Unit 13 grammar

主备人：叶英宏 审核人：孙晨晨

情态动词表示推测

[语法初识]

原句感知 自主探究 (1)must表示非常有把握的推测，意为“一定”；must be/do是对现在动作或状态的推测，如句⑥；must be ①I think my French tutor might know one of them. doing是对现在进行的动作的推测，如句④；must ②They might be sheltering in a have done是对过去情况的推测，如句⑦。 cave. ③They might have fallen behind. (2)may/might表示有一定可能的推测，意为 ④He looks upset. He must be having “可能，大概，也许”。may/might be/do是对现在some problems. ⑤You can't have failed the exam. ⑥I think the old woman must be a nice person. ⑦You are wet enough. You must have got caught in the rain. 对现在正在进行的动作的推测，如句②； may/might have done是对过去情况的推测，如 句③。 动作或状态的推测，如句①；may/might be doing是⑧He can't be home now. He just left (3)can't/couldn't表示否定推测，意为“不可能”。five minutes ago. ⑨Can he have lost his key? ⑩He can't be playing be doing是对现在正在进行的动作的推测，如句can't be/do是对现在动作或状态的推测，如句⑧；can't basketball.The teacher is talking to him B10；can't/couldn't have done是对过去情况的推测，about his homework. 如句⑤；can还可以用于疑问句，表示“可能”，如句⑨。 [语法剖析]

一、情态动词表示肯定的推测

肯定的推测一般用must, should, may(might)或could(不用can)，其中，must的语气最强，意为“肯定，准是，想必是”；should的语气次之，意为“很可能，应该”，指按常理推测；

高二英语导学案

may(might), could的语气最弱，意为“也许，可能”。

Someone must have been here last night. 昨晚一定有人来过。

即时演练1

用适当的情态动词填空

①She may have flown to Paris already.

②It's work hours now, she must be staying in the office. ③This job should be finished on time tomorrow.

④He must have gone home, for I haven't seen him up to now.

二、情态动词表示否定的推测

1．语气不很肯定时，常用may not, might not或could not，意为“可能不，也许不”。 2．否定语气较强时，则用can't，意为“根本不可能”“想必不会”，表示惊异、怀疑的感情色彩。

He can't be at home. 他不可能在家。(很有把握)

[名师指津] (1)could, might表示推测时，并不表示过去时态，只表示委婉语气。 (2)疑问句中的推测，往往用can或could。 —Could I use your cell phone! —Yes, you can.

——我可以用一下你的手机吗？ ——是的，可以。

即时演练2

完成句子

①The meeting can/could_not_be_put_off (不可能被推迟)． ②She might/may_not_come (可能不来) tomorrow, because she was ill. ③Yesterday, he might_have_been_late (可能迟到了)．

④She couldn't_have_missed (不可能错过) the good chance because she was looking for a job.

三、情态动词对不同时间情况的推测

1．“情态动词＋动词原形”表示对现在或将来情况的推测。 I don't know where she is; she may be in Wuhan.

高二英语导学案

我不知道她在哪儿，她有可能在武汉。

2．“情态动词＋现在进行时”表示对现在或将来正在进行的情况的推测。 At this moment, our teacher must be correcting our exam papers. 这时，我们的老师想必在批改我们试卷。

3．“情态动词＋完成时”表示对过去情况的推测。 The road is wet. It must have rained last night. 地面是湿的，昨天晚上一定下雨了。

[名师指津] 含must, may (might)的反义疑问句，反义疑问部分的动词形式根据它们后面的动词形式以及有无时间状语来确定。

You must/may (might) be hungry now, aren't you? 你一定/可能(或许)饿了，对吗？ You must have heard about it, haven't you? 你一定听说过这事了，对吗？

You must have watched the football match last night, didn't you? 昨天晚上你一定看过足球赛了，对吗？

4．“情态动词＋完成式”还可以用作虚拟语气，其结构是： (1)could have done本来能做……(实际未做)

(2)should/ought to have done本来应该做……(实际未做) (3)might have done本来可以……(实际未做) (4)needn't have done本来没有必要做……(实际做了) You could have done better, but you didn't try your best. 你本能做得更好，但你没有尽全力。

You should/ought to have refused her at the beginning. 你本应该在开始时就拒绝她的。 即时演练3

单句改错

①You needn't come here yesterday.needn't→needn't_have ②He must be waiting for you, but I'm not sure.must→may/might

③I didn't see you in the Party, but you should join in it.should_join→should_have_joined ④He has lived with her for a long time, so he might know her.might→must ⑤It must have rained last night, hasn't it？hasn't→didn't

[应用实战]

一、链接高考

高二英语导学案

情态动词填空

1．(2015·重庆高考改编)You must be Carol.You haven't changed a bit after all these years. 2．(2014·江西高考改编)Life is unpredictable; even the poorest might become the richest. 3．(2014·陕西高考改编)My book, TheHouseofHades, is missing. Who could have taken it? 4．(2013·四川高考改编)—Why are your eyes so red? Youcan't have slept well last night. —Yeah, I stayed up late writing a report.

5．(2013·湖南高考改编)He couldn't sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.

6．(2013·陕西高考改编)The children must have got lost in the woods; otherwise, they would have been at the lakeside camp as scheduled.

7．(2013·北京高考改编)—You needn't take an umbrella.It isn't going to rain. —Well, I don't know.It might do.