2021年大学英语四级语法精要

大学英语四级语法精要

Ⅰ动词(时态,语态,用法,省略,一致性等)

1. 时态

1)当前完毕进行时态(have/has been + -ing 分词构成)：动作或状态从过去某时开始,继续到当前,也许继续下去,也也许刚刚结束.

I’ve been writing letters for an hour.

I’ve been sitting in the garden.

2)过去完毕进行时(由had been + ing分词构成)：过去某个时刻此前始终在进行动作

I’d been working for some time when he called.

We had been waiting for her for two hours by the time she came.

3)将来完毕进行时：将来某个时刻此前始终在进行动作.

By next summer，he will have been working here for twenty years.

In another month’s time she’ll have been studying here for three years.

4)将来完毕时(由shall/will have + 过去分词构成)：将来某时会业已发生事.

I shall have finished this one before lunch.

They’ll have hit the year’s target by the end of October.

2. 语态

1) 可以有两种被动构造类型,例如:

He was said to be jealous of her success.

It was said that he was jealous of her success.

能同步合用于上述两个句型积极词普通都是表达“预计”,“相信”等意义动词,常用有assume,believe,expect,fear,feel,know,presume,report,say,suppose,underst and等.

It is supposed that the ship has been sunk.

The ship is supposed to have been sunk.

担当be supposed to 与不定式普通形式搭配时往往表达不批准义.例如:

Why are you driving so fast in this area?You are supposed to know the speed to know the speed limit. (你应当晓得速度限制)

2) 双宾语及宾补构造被动语态

a) 双宾语构造被动语态：双宾语构造变为被动语态时,可以把积极构造中一种宾语变为主语,另一种宾语依然保存在谓语背面,但多数是把

间接宾语变为主语.

He was asked a number of questions at the press conference.

Two days were allowed them for making the necessary preparations.

b) 宾补构造被动语态：

She was called Big Sister by everybody.

Then he was made a squad leader.

He was considered quite qualified for the job.

The room was always kept clean and tidy.

3. 短语动词

1) Vi + adv

The plane took off two hours late.

2) Vi + prep

They looked round the Cathedral.

3) Vi + prep (有被动语态)

She’s looking after her sister’s children.

The children were always well looked after.

4) Vi + adv + prep

I began to look forward to their visits.

5) Vt + O + adv

Some women choose to stay at home and bring up their children.

The children were brought up by their mother.

They took him on.

6) Vt + adv + O (无被动语态)

I am trying to give up smoking.

7) Vt + O + prep

We talked Donald into agreement.

4. 省略

1) 在以as，than，when，if，unless等引导从句中省略：在有些状语从句中,如果谓语包具有动词be,主语又和主句主语一致a),或者主语是it b),就经常可以把从句中主语和谓语一某些(特别是动词be)省略掉.

a) Look out for cars when crossing the street.

When taken according to the directions，the drug has no side effects. While there he joined in voluntary labour on a project.

Although not yet six months old，she was able to walk without support. If not well managed，irrigation can be harmful.

Though reduced in numbers，they gained in fighting capacity.

This viewpoint，however understandable，is wrong.

Enemies，once discovered，were tightly encircled and completely wiped out.

She hurriedly left the room as though/if angry.