發(fā)布時(shí)間： 2016年04月20日

英語四級(jí)語法：情態(tài)動(dòng)詞

英語四級(jí)語法：情態(tài)動(dòng)詞

四級(jí)語法不知道怎么備考?先從常見的情態(tài)動(dòng)詞來了解，用好這些詞可以減輕句子的程度，還可以在翻譯或者四級(jí)作文的備考中起到作用，下面跟新東方在線英語四級(jí)頻道一起學(xué)習(xí)英語語法吧!

情態(tài)動(dòng)詞屬于非實(shí)意動(dòng)詞，它雖具有一定的詞義，但這種詞義并不完整，語法上也不能單獨(dú)構(gòu)成謂語，它必須和另一個(gè)實(shí)

情態(tài)動(dòng)詞屬于非實(shí)意動(dòng)詞，它雖具有一定的詞義，但這種詞義并不完整，語法上也不能單獨(dú)構(gòu)成謂語，它必須和另一個(gè)實(shí)意動(dòng)詞一起構(gòu)成謂語才能表達(dá)完整的意思。情態(tài)動(dòng)詞是一類非?；钴S的非實(shí)意動(dòng)詞，歸納起來，情態(tài)動(dòng)詞在句子中主要有三種用法：

1.情態(tài)動(dòng)詞的非推測性用法

其用法是用來表示能力、許可、必要、義務(wù)、命令、勸告、詢問、需要、應(yīng)該、敢于等概念或態(tài)度，這類情態(tài)動(dòng)詞有：can(could)，may(might)，shall(should)，will(would)，must，

oughtto，need，dare等，例如：

Children，you can eat something you like.

Everybody must pay the fare，but you need not do so right away.

How dare you come out without your parents’permission?

I would rather stay at home than go with you.

Ought not parents to give their child more care?

You are not so young;you should not do such silly things any more.

疑問句中的情態(tài)動(dòng)詞和答語中的情態(tài)動(dòng)詞有固定的搭配形式。例如：

-Could I borrow your bike for a while?

-Yes，you can.(-Yes，please.)

-No，you can not.

-May I discuss something on practicing spoken English with you now?

-Yes，you may.(-Yes，of course.)

-No，you mustn’t.

-Need everyone fill in this application form immediately?

-Yes，everyone must.(Yes，everyone do.)

-No，they needn’t.

-Must we hand out emergency rations to these famine refugees this instant?

-Yes，you must.

-No，you they needn’t.

-No，you don’t have to.

2.情態(tài)動(dòng)詞的推測性用法

人們常常會(huì)對(duì)客觀事物做出自己的判斷，當(dāng)情態(tài)動(dòng)詞用來表示說話人對(duì)事物的推測、判斷時(shí)，就具有情態(tài)動(dòng)詞的推測性用法?？梢杂米魍茰y的情態(tài)動(dòng)詞有can，could，may，might，must，ought to， should，will和would。它們做出可能性的推測、判斷、預(yù)料的程度是不同的，might最弱、最沒有把握，而must最強(qiáng)、把握最大。例如：

It’s nine o’clock.My friend couldn’t come to see me.

This boy must fail in exam from his sad face.

It’s five past eight.There ought to be many students waiting for the door opening.

She should be a clerk in foreign company according to her formal dress.

He may not be fine in these days.

They were ready for a strong earthquake which might occur.

有時(shí)，情態(tài)動(dòng)詞用不同的動(dòng)詞時(shí)態(tài)來推測表達(dá)對(duì)不同時(shí)間的事物的推測，例如：

My friend may be still sleeping at home now.(對(duì)現(xiàn)在說話時(shí)正在發(fā)生的事物的推測)

Can we be working at the same company next year?(對(duì)將來的推測)

His clothes is wet.He must have forgotten to bring the umbrella.(對(duì)已經(jīng)完成的情況的推測)

3.情態(tài)動(dòng)詞用于虛擬語氣

A：提出一個(gè)假設(shè)的條件，純粹的展望或提出命令、要求。有部分情態(tài)動(dòng)詞的過去時(shí)態(tài)常用于這種用法。