245 表示知道和思想等的动词之后的不定式

 

A assume believe consider feel know suppose understand 等之后可接宾语+ to be

I consider him to be the best candidate

我认为他是最佳人选。

that+普通动词的结构比这常用得多:

I consider that he is the best candidate

(译文同上。)

宾语+不定式与 think estimate presume 等动词连用是极少见的。这种表达方法常用that从句来代替:

I think that he is the best player

我认为他是最好的演奏家/演员/运动员。

It is estimated that the vase is 2000 years old

据估计这个花瓶有两千年历史。

B 然而,如果这些动词是以被动形式出现的,那么它们后面常常带不定式而不是带that结构:

He is known to be honest.相当于:

It is known that he is honest

众所周知,他是个老实人。

He is thought to be the best player相当于:

It is thought that he is

人们认为他是最好的演奏家/演员/运动员。

This vase is estimated to be 2000 years old

据估计这个花瓶有两千年历史。

C 注意suppose的被动态时往往有责任或义务之意:

You are supposed to know the laws of your own country

你应该懂得你们自己国家的法律。相当于:

It is your duty to knowYou are expected to know

你有义务懂/人们认为你该懂……

D 在这些动词后面也可以用不定式的进行式:

He is thought to be hiding in the woods

人们以为他正躲在森林里。(人们认为他正躲着。)

He is supposed to be washing the car

他应该在洗车。(他该正在洗它。)

E 如果想到的是早先发生过的动作,则用不定式的完成式:

They are believed to have landed in America

人们相信他们在美洲上了岸。(据信他们已登上了。)

supppose+不定式的完成式不一定有责任或义务之意。

They are supposed to have discovered America.相当于:

It is thought that they did

人们认为是他们发现了美洲。

You are supposed to have read the instructions(你应已看过操作说明)通常意味着你本应看过。

(关于动词的被动式之后的不定式结构,另参见第306节。)