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牛津实用英语语法 306 被动态动词后的不定式结构

分类: 英语学习方法 

A 不定式结构用在acknowledge,assume,believe,claim,consider,estimate,feel,find,know,presume,report,say,think,under- stand等动词之后。(参见第245节。)

People consider/know/think等that he is…这类句子有两种被动形式:

It is considered/known/thought etc.that he is…

He is considered/known/thought etc.to be…

同样:

People said that he was jealous of her.

人们说他妒忌她。相当于:

It was said that he was…

He was said to be jealous of her.

据说他妒忌她。

在这两种结构中,用不定式的后一结构比较简洁。它主要用于be,尽管有时其他动词的不定式也可以这样用:

He is thought to have information which will be useful to the police.

人们认为他掌握了对警察有用的情况。

如句中所想到的内容涉及到以前的动作,则使用不定式的完成式,因此:

People believed that he was…相当于:

It was believed that he was/He was believed to have been…

People know that he was…相当于:

It is known that he was/He is known to have been…

这种结构可与任何动词的不定式的完成式连用。

B 不定式结构用在suppose后

1 suppose的被动态之后可以接任何动词的不定式的一般式,但这种结构通常都含有这是一种责任、义务的意思,因此并不是同suppose的主动态(常意为“推测”)完全对应的形式:

You are supposed to know how to drive.

你本该会开车。相当于:

It is your duty to know/You should know how to drive.

会开车是你的责任。/你该知道怎么开车。

但He is supposed to be in Paris既可能意思是他应该在那里,也可能是指人们猜想他在那里。

2 suppose的被动态后面同样可以跟任何动词的不定式的完成式。这种结构可以有责任和义务的含义,但也常常没有这种含义:

You are supposed to have finished.相当于:

You should have finished.

你早就应该完成了。

但是:

He is supposed to have escaped disguised as a woman.相当于:

People suppose that he escaped…

据猜测他是乔装打扮成女人逃跑的。

C 用在被动态动词后面的不定式通常是带to的不定式,尽管主动态动词后面可能带的是不带to的不定式:

主动态:         We saw them go out.

                       我们看见他们出去了。

被动态:         They were seen to go out.

                       有人看见他们出去了。

主动态:         He made us work.

                       他强迫我们干活。

被动态:         We were made to work.

                       我们被迫干活。

然而,惟独let的被动态后面的不定式不带to:

主动态:       They let us go.

                     他们让我们走了。

被动态:       We were let go.

                     我们被允许走开。

D 不定式的进行式可用于如下动词的被动式之后:believe, know,report,say,suppose,think,understand等。

He is believed/known/said/supposed/thought to be living abroad.相当于:

People believe/know/say/suppose/think that he is living abroad.

据信/据知/据说/据猜测/据认为他住在国外。

You are supposed to be working.相当于:

You should be working.

你本应在工作。

在这里也可用不定式的完成进行式:

He is believed to have been waiting for a message.相当于:

People believed that he was waiting for a message.

据信他当时一直在等待消息。

You are supposed to have been working.相当于:

You should have been working.

你那时本该一直在工作。


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