名词性从句讲解(2)

名词性从句讲解（2 ）

应城市第三高级中学刘琪

一．表语从句：在复合句中，位于系动词之后作表语的从句叫表语从句。引导表语从句的关联词与引导主语从句的关联词大致一样，表语从句位于系动词后，有时用as if引导。

1.that 引导表语从句，无词义，只起连接作用，不可省。

2.联系动词可为be,look,seem,sound,appear等。

3.主语可为名词

fact,truth,cause,question,explanation,trouble,assumption,belief等，代词this,that,these,it等。

4.whether 引导表语从句

The fact is that we have lost the game.

That’s just what I want.

This is where our problem lies.

That is why he didn’t come to the meeting.

It looks as if it is going to rain.

China is not what it used to be.

The question is whether the enemy is marching towards us。

【注意】

1.当主语是reason时，表语从句要用that引导而不是because。

The reason why he was late was that he missed the train by one minute this morning.

2.whether可引导表语从句，但与之同义的if却通常不用于引导表语从句。

3.That is why…译为“这就是……的原因”。

其中why引导的名词性从句在句中做表语，该句型通常用于针对前面已经说过的原因进行总结。

That is why you see this woman before you know.

That is why I came.

区别：①That is why ……与That is the reason why …同义，只不过从语法结构上讲，前者中的why引导表语从句，后者中的why引导定语从句。

That is (the reason ) why I cannot agree.

②That is because …句型中从属连词because引导的名词性从句在此做表语，意为“这就是为什么……/因为……”。

That is because …指原因或理由。

That is why … 指由于各种原因所造成的后果。

He didn not see the film last night. That is because he had to help his little sister with her homework.

He had seen the film before. That is why he did not see it last night. 二．同位语从句：同位语从句说明其前面的名词的具体内容。同位语从句通常由that引导，可用于同位语从句的名词有advice、demand、doubt、fact、hope、idea、information、message、news、order、problem、promise、question、request、suggestion、truth、wish、word等。

The news that we won the game is exciting.

I have no idea when he will come back home.

The thought came to him that Mary had probably fallen ill.

（一）理解同位语从句的含义，把握同位语从句的实质

同位语从句一般用that, whether，what, which, who, when, where, why, how 等词引导，常放在fact, news, idea, truth, hope, problem, information, wish,promise, answer, evidence, report, explanation, suggestion, conclusion等抽象名词后面，说明该名词的具体内容。换言之，同位语从句和所修饰的名词在内容上为同一关系，对其内容作进一步说明。

The news that they had won the game soon spread over the whole school.

（二）正确运用同位语从句的引导词，准确把握同位语从句

1.如同位语从句意义完整，应用that引导同位语从句。（即that 不充当任何成分，只起连接作用，不可省略）

The general gave the order that the soldiers should cross the river at once.

2.如同位语从句意义不完整，需增加"是否"的含义，应用whether引导同位语从句。（if不能引导同位语从句）

We'll discuss the problem whether the sports meeting will be held on time.

3.如同位语从句意义不完整，需增加"什么时候"、"什么地点"、"什么方式"等含义，应用when, where, how等词引导同位语从句。

I have no idea when he will be back.

I have no impression how he went home, perhaps by bike.

4.当主句的谓语较短，而同位语从句较长时，同位语从句常后置。

The thought came to him that maybe the enemy had fled the city.

5.表示“命令、要求、建议”的名词order, demand, suggestion等后接同位语从句时，从句的谓语要用虚拟语气，即“(should)＋动词原形”。如：

They mainly discussed the suggestion that a big dam (should) be built there。

（三）把握同位语从句和定语从句的区别

同位语从句和定语从句相似，都放在某一名词或代词后面，但同位语从句不同于定语从句。同位语从句对名词加以补充说明，是名词全部内容的体现，且名词和同位语从句的引导词均不在从句中作成分；定语从句说明先行词的性质与特征，与先行词是修饰与被修饰的关系，且名词和定语从句的引导词均在从句中作成分.区分时可以在先行词与与从句之间加一个系动词be,使之构成一个新句子，如果句子通顺且符合逻辑，则为同位语从句，反之，则为定语从句

1. 从词类上区别

同位语从句前面的名词只能是

idea,fact,news,hope,belief,suggestion,proposal,word,thought,doubt,tru th,possibility,promise,order等有一定内涵的名词,而定语从句的先行词可以是名词,代词.如:

We are not looking into the question whether he is worth trusting.