名詞性從句（Noun Clauses）

在句子中起名詞作用的句子叫名詞性從句。名詞性從句的功能相當(dāng)于名詞詞組，它能在復(fù)合句中作主語、賓語、表語、同位語等。根據(jù)它在句中不同的語法功能，名詞性從句分為主語從句、賓語從句、表語從句和同位語從句。在名詞性從句中，連接詞that既沒有實(shí)際意義，又不充當(dāng)任何成分，只起引導(dǎo)從句的作用,引導(dǎo)賓語從句時(shí)經(jīng)常省去。

一、主語從句(The Subject Clause）：在復(fù)合句中作主句的主語。為保持句子結(jié)構(gòu)平衡，主語從句通常被置于句末，而用it作形式主語。

That light travels in straight line is known to all.

When the plane is to take off hasn't been announced.

It was my fault that I had him play football yesterday afternoon.

It is important that we should go to the school to talk with the teacher.

It is still unknown which team will win the match.

二、賓語從句(The Object Clause）：主要作及物動詞的賓語，有時(shí)置于介詞或形容詞之后。

He said(that)his father had come back from the United States.

He asked how much I paid for the violin.

No one can be sure what man will look like in a million years.

如果賓語從句帶有補(bǔ)足語，通常用it作形式賓語，而把賓語從句置于補(bǔ)足語之后。

I think it necessary that we should pay close attention to SARS.

We all feel it our duty that we should serve the people heart and soul.