情态动词的三大基本特征（情态动词表推测讲练结合）

情态动词表推测的用法及练习，我来为大家讲解一下关于情态动词的三大基本特征?跟着小编一起来看一看吧!

情态动词的三大基本特征

情态动词表推测的用法及练习

表推测时，只使用must, can, may, might, could, might not , could not, may not和can't这九个词。表达的语气依次递减：

must:一定（语气肯定）

may：也许（不很肯定）

might：或许（比may语气更弱）

may not：也许不（表否定）

can't：一定不（must的反义）

一、情态动词表推测的三种形式

1.情态动词 动词原形，表示对现在或将来某动作或状态的推测。

比如must do，can't be

例：It can't be true.这不可能是真的。

It can’t rain tomorrow.明天可能要下雨。

2.情态动词 be doing表示推测某动作可能正在进行。

比如must be doing等。

例：Lily must be doing her homework now.莉莉现在一定是在做作业。

3.情态动词 have done表示对过去行为或动作的推测。

比如must have done等。

例：He must have misunderstood me.他一定是误解了我。

二、几个情态动词 have done的特定用法。

1. should have done 表示“过去本应该做某事却未做。”

其否定结构 shouldn't have done 表示 “过去本不该做某事却做了。”

2. ought to have done 表示“过去本应该做某事却未做。”

其否定结构 oughtn't to have done 表示 “过去本不该做某事却做了。”

3. need have done 表示“过去本有必要做某事却未做。”

其否定结构 needn't have done 表示 “过去本没必要做某事却做了。”

4. could (不能用 can) have done 表示“过去本能够做某事却未做。”

注意：其否定形式 couldn't have done 没有虚拟语气的用法，couldn't have done 只能表推测，相当于 can't have done，意为：“过去不可能做了某事。”

5. might (不能用 may) have done 表示“过去本可以做某事却未做。”

注意：其否定形式 might not have done 没有虚拟语气的用法，might not have done 只能表推测，相当于 may not have done，意为：“过去可能没有做某事。”

三、例题

1. Sorry I'm late. I ________ have turned off the alarm clock and gone back to sleep again.

A. might 　　　　B. should 　　　　　C. can 　　　　　　D. will

答案为 A。表推测的用法。句意：对不起，我迟到了。我（当时）兴许是关了闹钟又回去睡觉了。might 相当于 may, 但语气更加不肯定。

2. I was really anxious about you. You_________ home without a word.

A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave

答案为 B。虚拟语气用法。句意：我（那时）真地很担心你。你本不应该不留个话就离开家。

3. — I’ll tell Mary about her new job tomorrow.

— You________ her last week.

A．ought to tell B．would have told C．must tell D．should have told

答案为 D。虚拟语气用法。句意：---我明天要告诉她我的新工作的情况。 ---你本应该上周告诉她。

4. — Tom graduated from college at a very young age.

— Oh, he ______ have been a very smart boy then.

A. could B. should C. might D. must

答案为 D。表推测的用法。句意：——汤姆很年轻的时候就大学毕业了。——哦，他肯定是一个很聪明的男孩儿。

5. He _______ have completed his work; otherwise, he wouldn't be enjoying himself by the seaside.

A. should B. must C. wouldn't D. can't

答案为 B。用法同4题。句意：他肯定做完了工作，不然他就不会在海边痛快地玩儿了。

6. — Do you know where David is? I couldn't find him anywhere.

— Well. He have gone far—his coat's still here.

A．shouldn't B．mustn't C．can't D．wouldn't

答案为 C。表推测的用法。句意：—你知道大卫在哪儿吗？我哪儿也找不到他。—瞧，他不可能走远—他的上衣还在这儿呢。can't 相当与 couldn't，但后者语气更加委婉。

四、练习

1. — The woman biologist stayed in Africa studying wild animals for 13 years before she returned.

— Oh, dear! She _______ a lot of difficulties!

A. may go through B. might go through

C. ought to have gone through D. must have gone through

2. I have lost one of my gloves. I ________ it somewhere.

　　A. must drop B. must have dropped

C. must be dropping D. must have been dropped

3. Mr. White _____ at 8:30 for the meeting, but he didn't show up.

A. should have arrived B. should arrive

C. should have had arrived D. should be arriving

4. He paid for a seat, when he ______ have entered free.

A. could B. would C. must D. need

5. — Tom is never late for work. Why is he absent today?

— Something ________ to him.

A．must happen B．should have happened

C．could have happened D．must have happened

6. I _______ have been more than six years old when the accident happened.

A. shouldn't B. couldn't C. mustn't D. needn't

7. This cake is very sweet. You __________ a lot of sugar in it.

A．should put B．could have put C．might put D．must have put

Key: D B A A D B D

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