考研同学之所以对一些英语长难句不是很理解，归根结底是对语法掌握不够透彻。针对此问题，小编对考研英语语法进行了汇总，希望各位同学能把各语法点弄明白。
被动语态
(一)简介
在英语中，语态是动词的一种形式，表示主语和谓语的关系。英语动词有两种语态，即主动语态和被动语态。主动语态(active voice) 表示主语是动作的执行者;被动语态(passive voice)表示主语是动作的承受者。如：
Saddam is being tried. 萨达姆正在接受审判。
The Iraqi government is trying Saddam. 伊拉克政府正在审判萨达姆。
More and more people use computers now.(主动语态)
Computers are more and more widely used now.(被动语态)
English is spoken all over the world. (被动语态)
(二)英汉两种语言在表达被动方式上的差异
汉语表达被动语态非常简单明了，用“被”“遭”“受”等词来表示，如“被捕”、“被杀”、“受到凌辱”等。而英语表达被动的方式也不复杂，用“助动词be+动词的过去分词”表示。其中助动词be有人称、数量和时态的变化，而这正是英语被动语态的难点。
(三)被动语态的构成
被动语态由“be+及物动词的过去分词”构成。这里要强调一定是及物动词的过去分词，因为不及物动词不能带宾语，也就不可能有被动语态。英语主动语态有16个时态;被动语态常用的有8个，以give为例说明如下：
时态动词形式
一般现在时Am/is/are given
一般过去时Was/were given
一般将来时Shall/will be given
现在进行时Am/is/are being given
过去进行时Was/were being given
过去将来时Should/would be given
现在完成时Has/have been given
过去完成时Had been given
被动语态的疑问句是将第一个助动词移到主语之前、句末用问号;否定式是在第一个助动词后加not或never等其他否定词、句末用句号。如：
“During the interview, were you asked questions in English?” “No, I wasn’t asked questions in English.” “面试的时候，用英语问你问题了吗?”“没有，没有用英语问我问题。”
The origin of the universe will probably never be explained. 宇宙的起源大概永远也不会被解释清楚。
Is the restaurant being decorated? 那家餐馆正在装修吗?
The restaurant is not being decorated. In the fact the restaurant has never been decorated。 那家餐馆没有在装修。实际上，那家餐馆从来没有装修过。
(四)被动语态的用法
1、不知道或没有必要指出动作的执行者。换个说法，有一件事情不知道是谁干的或者不想说出是谁干的，这时就用被动语态。例如：
I felt a littlie nervous when I was being interviewed. 我接受面试的时候，有点紧张。
These fighters are imported from Russia. 这些战斗机是从俄国进口的。
That place has been turned into a swimming pool. 那个地方已被变成游泳池。
2、说话或发表意见时，为了显得客观公正，也常用被动语态
He’s said/believed/reported to be in the U. S. A. 据说/据信/据报道他在美国。
还有下列常用句型(that后面跟句子)：
It is said that……. 据说
It is reported that……. 据报道
It is hoped that……. 希望
It is believed that……. 人们相信
It is announced that……. 据宣布
it is (well) known that……. 众所周知
It has been decided that……. 已经决定
It is supposed that……. 人们认为
It is suggested that……. 有人建议
It must be remembered that……. 务必记住
It is taken for granted that……. 被视为当然
(五)主动句变被动句的注意事项
一是时态不能改变;二是变为被动语态后，谓语动词要和被动语态的主语在人称、数上保持一致。还要作如下变动：把主动语态的宾语变为被动语态的主语;主动语态的主语放在by的后面，组成介词短语，再把这个介词短语放在被动语态的谓语动词之后。在动作的执行者无须说明或不必要强调时，by短语可以省略。例如：
They will open a new supermarket there soon. 他们很快将在那里开办个新超市。
A new supermarket will be opened there soon. 一个新超市不久将在那里开办。
The doctor gave two lectures in English. 那位医生用英语讲了两次课。
Two lectures were given by the doctor in English. 由那位医生用英语讲了两次课。
Somebody has warned us to be careful of rats. 有人警告我们要当心老鼠。
We have been warned to be careful of rats. 我们受到警告，要当心老鼠。
如果主动语态有两个宾语(直接宾语和间接宾语)，变为被动语态时，可将其中任何一个宾语变为主语，另一个不变。但较常见的是将间接宾语变为被动语态的主语。
The reporters asked the president some questions. 记者们问了总统一些问题。
The president was asked some questions by the reporters. ( 变间接宾语为主语)
Some questions were asked the president by the reporters. (变直接宾语为主语)
We have given him a job. 我们已给了他一个工作。
He has been given a job. (变间接宾语为主语)
A job has been given (to) him. (变直接宾语为主语)
