名词性从句教师（高中）

例如：The reason for his success is that he worked hard. The reason why he was absent was that he was ill. (四)because和why引导表语从句的句型

This/That/It is because…含义为“这是因为…”或“这是由于…的缘故”（强调原因） This/That/It is why…含义为“这就是…的原因（强调结果） 例如：That is because thy are too careful in their studies. That was why he fell ill.

I was late for school. That is because it was raining hard. It was raining hard. That is why I was late for school.

五、同位语从句

（一） 同位语从句的基本用法

同位语从句通常说明主句中的名词，进一步解释这些名词的具体内容。这些名词一般是抽象名词，常见的有： answer idea principle 回答 想法 原则 belief certainty conclusion decision discovery doubt evidence explanation fact hope 相信 肯定 结论 决定 发现 怀疑 证据 解释 事实 希望 information knowledge law likelihood news opinion order possibility probability problem 消息 知识 法律 可能 消息 观点 命令 可能（性） 可能 问题 promise question report risk rule rumour statement suggestion thought truth 许诺 问题 报告 冒险 规定 传闻 声明 建议 思想 真理 同位语从句一般由that引导，但也可以用what,which,who,when,where,why,how或whether(if)引导。

例如：Sixteen years of being addressd thus left Harry in no doubt whom his uncle was calling. Nevertheless, he did not immediately respond.

The question whether we should have another meeting must be decided soon. The idea that you can do the work well without thinking is quite wrong. I have no idea when Mr. Zhang will leave for Paris. She had given them a hint what they should do. He raised the question how we could get the money.

（二） 同位语从句与先行词的隔离

同位语从句有时不紧跟在它所说明的名词后面，而被别的词隔开，目的在于使句子保持平衡。

例如： An idea came to her that she might have left her wallet in the restaurant. The question sometimes comes to my mind whether it was worth the effort.

He got a message form Mr. Johnson that the manager could not see him that afternoon.

(三)同位语从句与定语从句的区别

同位语从句修饰少数表示丑行意义的名词，引导同位语从句的that只起连接主从句的作用，不作任何成分，一般不省略；定语从句可以修饰一切名词，引导定语从句的that除了起连接作用外，在从句中作主语、宾语或表语，that作宾语时可以省略。

例如：The news that our football team won is true.(同位) The news that you heard isn’t true.（定语）

He expressed the hope that he would come over to visit China again.（同位） The last thing that I will do is to hurt her.（定语） 六、名词性从句需要注意的其他问题

（一） that与what的用法比较

that可以引出名词性从句，在从句中不充当任何成分；that也可以引出定语从句，在从句中可以充当主语、宾语或表语。what只能引出名词性从句，在从句中充当主语、宾语、表语或宾语补足语。

例如：This is what is to be discussed. He realized (that) he was wrong.

We removed the tree that fell across the road.

（二） whether与if的用法比较

1. 下列情况只能用whether:引导主语从句、表语从句、同位语从句、介词宾

语从句、直接跟or not、用于不定式之前、作discuss的宾语从句或宾语从句位于主句之前时。

例如：Whether they will come to help us does not matter much. The problem is whether we need it.

There is no evidence whether he has found a new element.

He was worried about whether he passed the English examination. Do you know whether or not he will come? I don’t know whether or not he will come? We discussed whether Mary could join us. Whether this is true or not, I can’t say. 2. whether或if均可引出动词宾语从句

例如：He asked me if/ whether I would attend the meeting. 注意：引导否定的宾语从句时，通常用if,不用whether. I asked him if he did not know her.

3. whether引导让步状语从句，if引导条件状语从句。例如：

Whether you like it or not, you must go with us. We sat on the grass if it was fine.

（三） what与which的用法比较

what和which既可指人，也可指物，两者都具有名词和形容词特征，都可以作主语、宾语、表语和定语，但which一般用于有一定选择范围的情况，what则用于无选择范围或不清楚是什么的情况。 例如：I wonder which he likes best. I wonder what he likes.

（四） who与whoever的用法比较

who引导的名词性从句只有它本身疑问的含义“谁”：而whoever意为anyone/ the person+who,相当于定语从句中的“先行词+引导词”。Whoever, whatever, whichever与whoever有类似的用法。

例如：Who will go is not important.

Give the book to whoever you like. You may choose whichever you want.

Whoever leaves the room last ought to turn off the light. Whatever is worth doing at all is worth doing well.

(五)that与whether的用法比较

在名词性从句中，如果句意明确、没有疑问，那么就用that引出名词性从句，表示一个事实；如果句意不明确，有疑问，就用whether引出名词性从句，表示“是否…”。

例如：The news that our team had won thrilled us all. He wasn’t sure whether he ought to laugh or cry.

Whether one can succeed depends oon how hard he works. You will of course understand that my point of view is different.

(六)两个连词都不能省去

如果名词性从句的连词之后又紧跟一个连词引起名词性从句中的主语从句或状语从句时，两个连词都不能省去。

例如：I wonder whether what I have said has done her wrong.

Then I became very angry, and decided that if anyone should set me free, I would kill him at once.(that宾语从句中有一个条件状语从句)

It is well-known that what a person eats causes changes in the body.