2021年英语四级语法必备知识点

　　要想顺利通过英语四级考试，考前的准备很重要。下面是小编给大家分享的英语四级语法必备知识点，大家可以作为学习的参考。

　　英语四级语法必备知识点

　　动词(时态,语态,用法,省略,一致性等)

　　时态

　　1)现在完成进行时态 (have/has been + -ing 分词构成): 动作或状态从过去某时开始,继续到现在,可能继续下去,也可能刚刚结束.

　　I’ve been writing letters for an hour.

　　I’ve been sitting in the garden.

　　2)过去完成进行时(由had been + ing分词构成): 过去某个时刻以前一直在进行的动作

　　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)将来完成进行时: 将来某个时刻以前一直在进行的动作.

　　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)将来完成时(由shall/will have + 过去分词构成): 将来某时已发生的事.

　　I shall have finished this one before lunch.

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

　　语态

　　可以有两种被动结构的类型,例如:

　　He was said to be jealous of her success.

　　It was said that he was jealous of her success.

　　能同时适用于上述两个句型的主动词通常都是表示“估计”,“相信”等意义的动词,常见的有assume,believe,expect,fear,feel,know,presume,report,say,suppose,understand等.

　　It is supposed that the ship has been sunk.

　　The ship is supposed to have been sunk.

　　担当be supposed to 与不定式的一般形式搭配时往往表示不同的意义.例如:

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

　　双宾语及宾补结构的被动语态

　　双宾语结构的被动语态: 双宾语结构变为被动语态时,可以把主动结构中的一个宾语变为主语,另一个宾语仍然保留在谓语后面,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.

　　宾补结构的被动语态:

　　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.

　　短语动词

　　Vi + adv

　　The plane took off two hours late.

　　Vi + prep

　　They looked round the Cathedral.

　　Vi + prep (有被动语态)

　　She’s looking after her sister’s children.

　　The children were always well looked after.

　　Vi + adv + prep

　　I began to look forward to their visits.

　　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.

　　Vt + adv + O (无被动语态)

　　I am trying to give up smoking.

　　Vt + O + prep

　　We talked Donald into agreement.

　　在以as, than, when, if, unless等引导的从句中的省略:

　　在有些状语从句中,如果谓语包含有动词be,主语又和主句的主语一致a),或者主语是it b),就常常可以把从句中的主语和谓语的一部分(特别是动词be)省略掉.

　　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.

　　She worked extremely hard though still rather poor in health.

　　Fill in the application as instructed.

　　Whenever known, such facts should be reported.

　　The documents will be returned as soon as signed.

　　He said that no acrobat could ever perform those daring feats unless trained very young.

　　Once having made a promise, you should keep it.

　　If necessary I’ll have the letter duplicated.

　　Fill in the blanks with articles where(ver) necessary.

　　If possible, I should like to have two copies of it.

　　As scheduled, they met on January 20 at the Chinese Embassy.

　　在以than a) 或 as b) 引起的从句中,常会有一些成分省略.

　　He told me not to use more material than (it is) necessary.

　　We should think more of the collective than of ourselves.

　　They worked with as much enthusiasm as young people (did).

　　He is now a vice-manager, but still often works in the kitchen as before.

　　Their training is free, as is all education.

　　We will, as always, stand on your side.

　　错误的省略

　　His life is as fully committed to books as anyone I know.

　　While standing there in her nightgown, two bullets struck the wall beside her.

　　一致

　　如果主语是单数,尽管后面跟有with, together with, as well as, as much as, no less than, more than等引导的短语,谓语动词仍旧用单数形式.

　　Terry, along with her friend, goes skating every Saturday.

　　An expert, together with some assistants, was sent to help in this work.

　　The captain, as well as the coaches, was disappointed in the team.

　　备考英语四级需要大量的积累单词和掌握语法，以上就是小编给大家分享的英语四级语法必备知识点，希望可以给大家带来帮助。