That引导的名词性从句解析

名词性从句（Noun clause）是在句子中起名词作用的句子。 名词性从句的功能相当于名词词组， 它在复合句中能担任主语、宾语、表语、同位语、介词宾语等，因此根据它在句中不同的语法功能，名词性从句又可分别称为主语从句、宾语从句、表语从句和同位语从句。

引导名词性从句的连接词 ， 可分为三类：

连接词：that,whether,if不充当从句的任何成分）

连接代词：what, whatever, who, whoever, whom, whose, which.

连接副词：when, where, how, why

不可省略的连词：

1.介词后的连词   2.引导主语从句和同位语从句的连词不可省略。

That she was chosen made us very happy.  /  We heard the news that our team had won.

比较：whether与if均为"是否"的意思。 但在下列情况下，whether不能被if取代：

1. whether引导主语从句并在句首   2.引导表语从句

3. whether从句作介词宾语         4.从句后有"or not"

Whether he will come is not clear.

大部分连接词引导的主语从句都可以置于句末，用it充当形式主语。

It is not important who will go.  /  It is still unknown which team will win the match.

名词性that-从句

1）  由从属连词that引导的从句叫做名词性that-从句。That只起连接主句和从句的作用，

在从句中不担任任何成分，本身也没有词义。名词性that-从句在句中能充当主 语、宾语、表语、同位语和形容词宾语。

例如：

A主语：That he is still alive is sheer luck.他还活着全靠运气。

B宾语：John said that he was leaving for London on Wednesday.约翰说他星期三要到伦敦去。

C表语：The fact is that he has not been seen recently.事实是近来谁也没有见过他。

D同位语：The fact that he has not been seen recently disturbs everyone in his office.近来谁也没有见过他，这一事实令办公室所有的人不安。

E形容词宾语：I am glad that you are satisfied with your job.你对工作满意我感到很高兴。

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2）That-从句作主语通常用it作先行词，而将that-从句置于句末，例如：

It is quite clear that the whole project is doomed to failure.很清楚，整个计划注定要失败。

It's a pity that you should have to leave.你非走不可真是件憾事。

用it作形式主语的that-从句有以下四种不同的搭配关系：

It is quite clear that the whole project is doomed to failure.很清楚，整个计划注定要失败。

a. It + be +形容词+ that-从句

It is necessary that…　　　 有必要……

It is important that…　　　 重要的是……

It is obvious that…　　　　 很明显……

It is important that student to discuss the questions with teachers .

b. It + be + -ed分词+ that-从句

It is believed that…　　　　　人们相信……

It is known to all that…　　　从所周知……

It has been decided that…　　 已决定……

It is known to all that The Great Wall is in China . 众所周知长城在中国。

c. It + be +名词+ that-从句

It is common knowledge that…　 ……是常识

It is a surprise that…　　 令人惊奇的是……

It is a fact that…　　　　 事实是……

It's a pity that you should have to leave.你非走不可真是件憾事。

d. It +不及物动词+ that-分句

It appears that…　　　　　　似乎……

It happens that…　　　　　　碰巧……

It occurred to me that…　　 我突然想起……

It doesn't appear that we'll have a sunny day tomorrow. 看来我们明天不会碰上好天气。

其实英语中名词性从句有很多种类，还有除了that之外的引导词可以引导名词性从句。关于that引导的名词性从句结构相对不复杂，有时候为了方便会把that省略掉，完全不影响语句的语法结构，并且意思也表达完整。把以上这些句式学会掌握了，可以帮助写作增加光彩。