情态动词全解析

情态动词全解析

一、何谓―情态动词‖？

情态动词主要用来表示说话人的情感、态度等，是中学英语语法的重点，也是高考的热点，是单项填空必考的一个知识点。情态动词在近五年高考中主要考查四点：情态动词表示推测和可能性的用法；情态动词与虚拟语气；情态动词的表达―情感、态度、语气等‖，情态动词表示―必要性‖等方面的用法。

二、情态动词的特点

1.没有人称和数的变化。

2. 有些情态动词有过去式的变化:

e.g. will → would , can → could , may→ might ,d are → dared

三、情态动词的否定形式

情态动词+ not +动词原形can not: can't , must not: mustn't , need not : needn't

四、情态动词的用法及相互间的区别

[★★★]五、情态动词的解题例析

(1) 认真审题，结合所给出的语境，正确把握说话者的语气、情感、态度、观点等。

(2) 认真思考所给选项中情态动词的基本特征和用法，并结合语境推敲答案。

(3) 要注意把握时间概念。

情态动词无论是表达“推测和可能性”，还是表达“虚拟”这一概念，只要是对过去已经发生的事情进行描述，一律用“情态动词+have done”这一结构；对现在或将来的事情进行描述，用“情态动词+动词或系动词原形”。

★下面我们来看看常考的一些情态动词★

以下试题均来源于往年的高考试题，具有很强的针对性

（一）情态动词表示推测和可能性的用法

(1) must表示推测，意为―一定……‖，只能用于肯定句中。must have done意为：一定做过某事或某事肯定发生了。例如：

—She looks very happy. She ______ have passed the exam.

—I guess so. It’s not difficult after all.

A. should

B. could

C. must

D. might

(2) should (not) / ought (not) to在中表示根据常规或常识推测，表示―某事应该或不应该发生‖，语气比must或can’t / couldn’t稍弱。

例如：—How’s your tour around the North Lake? Is it beauti ful?

—It ________ be, but it is now heavily polluted.

A. will

B. would

C. should

D. must

②There _________ be any difficulty about passing the road test since you have practiced a lot in the driving school.

A. mustn’t

B. shan’t

C. shouldn’t

D. needn’t

(3) can, could表达推测时，一般用于疑问句和否定句中；can用于肯定句中表示一种理论上的可能性，并不牵涉是否真的会发生，在这种用法中can只能与动词原形连用；could用于肯定句中，语气比may/ might更弱。例如：

①You ______ be hungry already — you had lunch only two hours ago!

A. wouldn’t

B. can’t

C. mustn’t

D. needn’t

②She ______ have left school, for her bike is still here.

A. can’t

B. wouldn’t

C. shouldn’t

D. needn’t

③It is usually warm in my hometown in March, but it _____ be rather cold sometime.

A. must

B. can

C. should

D. would

④Peter ____ be really difficult at times even though he’s a nice person in general.

A. shall

B. should

C. can

D. must

(4)may (not) / might (not)表达一种不太把握的推测，意为―或许，可能‖；might的语气比may 较婉转。

① Liza ___ well not want to go on the trip --- she hates traveling.

A. will

B. can

C. must

D. may

②Although this ____ sound like a simple task, great care is needed.

A. must

B. may

C. shall

D. should

③—I can’t find my purse anywhere.

—You __ have lost it while shopping.

A. may

B. can

C. should

D. would

（二）表达虚拟语气的情态动词

对过去的一种结果的假设或虚拟，用情态动词+have done这一结构，常用的有以下几个情态动词：

(1) should (not) / ought (not) to have done本（不）应该做某事，但却没有做或做了，含有责备或后悔之意。例如：

—I’m sorry. I _________at you the other day.

—Forget it. I was a bit out of control myself.

A. shouldn’t shout

B. shouldn’t have shouted

C. mustn’t shout C. mustn’t have shouted

(2) could have done本来能够做某事但未做。例如：

Thank you for all your hard work last week. I don’t think we ______ it without you.

A. can manage

B. could have managed

C. could manage

D. can have managed

(3) needn’t have done本没有必要做某事但却做了。要注意needn’t do则表达―没有必要去做某事‖，时间上应该是现在或将来。例如：

①—Catherine, I have cleaned the room for you.

—Thanks. You ________ it. I could manage it myself.

A. needn’t do

B. needn’t have done

C. mustn’t do

D. shouldn’t have done

② The boss has given everyone a special holiday, so we go to work tomorrow.

A. can’t

B. mustn’t

C. needn’t

D. shouldn’t

(4)would (not) have done本来(不)会发生某事，但却（发生了）或没有发生。常用于虚拟条件句或含蓄虚拟条件引导的虚拟语气，表示对过去所发生事情结果的假设。例如：

He hesitated for a moment before kicking the ball, otherwise, he ________ a goal.

A. had scored

B. scored

C. would score

D. would have scored

(5) might have done表示―本来可能……‖，但实际上没有发生的事。例如：

What a pity! Considering his ability and experience, he ________ better.

A. need have done

B. must have done

C. can have done

D. might have done （三）表达―情感、态度、语气‖ 等方面的情态动词

1. must表达―情感、态度、语气‖主要有以下用法：

(1) 表示主观的义务和必要，主要用于肯定句和疑问句，意思为―必须……，得……，要……‖；由must引起的疑问句，肯定回答要用must或have to，否定回答要用needn’t或don’t have to,意思是―不必‖。另外，must与have to都可以表示―必须‖这一含义。must表示一种主观的需要，而have to表示一种客观的需要，意思是―不得不‖，其否定形式是don’ have to。

例如：-What sort of house do you want to have? Something big?

--Well, it ______ be big--that's not important.

A. mustn't

B. needn't

C. can't

D. won't

(2) must的否定形式mustn’t表示禁止，意思是―不能，不许‖。例如：

When I was young, I was told that I ______ play with matches

A. wouldn't

B. needn't

C. mustn't

D. daren't

(3) must用于条件句或疑问句中，可以用来表示责备、抱怨的感情色彩，意思为―偏要，硬要、干嘛‖。①—May I smoke here?

—If you ____, choose a seat in the smoking section.

A. should

B. could

C. may

D. must

②John, look at the time. ___________ you play the piano at such a late hour?

A．Must B．Can C．May D．Need

2. should

(1) should应该，表示―责任和义务‖。例如：

According to the air traffic rules, you ___ switch off your mobile phone before boarding.

A. may

B. can

C. would

D. should