that除了可以用作指示代词或关系代词(引导定语从句)外，还常用作连接代词。此时，that无具体含义，也不在从句中充当任何句子成分，只起连接作用，用来引导下列四类名词性从句：

　　一、主语从句

　　that 引导的主语从句通常用it作形式主语，而将主语从句置于句末。例如：

　　①It was obvious that the driver could not control his car. 很明显驾驶员不能控制他的车子了。

　　②It is luck that he is still alive. 他仍然活着，真是走运。

　　③It is clear to me that he was telling the truth then. 他当时在讲真话，我对这点十分清楚。

　　注意：在正式文体中，为了强调从句，有时也可将从句置于句首，但主句为疑问句时只能将从句后置。所以，以上各例句可分别改写为：

　　①→That the driver could not control his car was obvious.

　　②→That he is still alive is luck.

　　③ →That he was telling the truth then is clear to me.

　　疑问句：

　　①→Was it obvious that the driver could not control his car?

　　② →Is it luck that he is still alive?

　　③→Is it clear to you that he was telling the truth then?

　　二、宾语从句

　　that引导的从句作宾语的情况最多。在非正式文体中，that一般可以省略。例如：

　　The boy dreamed (that) he was flying to the moon in a very big spaceship. 那个男孩梦到自己乘坐一艘很大的宇宙飞船飞向月球。

　　They thought (that) the car was expensive. 他们原以为这辆汽车太昂贵了。

　　—What did you assume from his attitude? 从他的态度中你猜到了什么？

　　—That he was frightened. 他感到害怕了。(主句I assumed被省略了)

　　注意：当that引导的宾语从句带补足语时, 或其主句的谓语为带介词的短语动词，如answer for (担保), count on (期待), depend on, insist on, see to (确保)等，接that引导的宾语从句时，要借助于it作形式宾语。例如：

　　He has made it clear that he has nothing to do with her. 他已经表明了他与她无关。

　　I am counting on it that you will come.我期待着你的到来。

　　She'll see to it that he goes ahead. 她会确保他继续进行。

　　三、表语从句

　　that引导的从句作表语，多表示事实、真理、理由或某人的意见、信念等的内容。例如：

　　The reason for his being late is that he missed the first bus. 他迟到的原因是没赶上第一班公共汽车。

　　Our belief is that everything will improve. 我们的信念是一切将会改善。

　　四、同位语从句

　　that引导的同位语从句之前常见的先行词有fact， news， hope， belief， order， truth， message， suggestion，word， idea， doubt等；that引导的同位语从句的作用是对先行词的具体内容作进一步的解释或补充说明。例如：

　　We must face the fact that we are short of water. 我们必须面对缺水这个事实。

　　Soon we received the order that we (should) stop fighting at once.不久我们就接到了立刻停止战斗的命令。

　　注意：如果主句的主语部分含有同位语从句，而主句的谓语部分单词又很少时，可以把主句的谓语部分提前，使同位语从句与先行词分开，以避免头重脚轻的情况。例如：

　　Word came that Saddam Hussein had been captured. 有消息传来萨达姆·侯赛因已被捉。

　　(文/陈光明； 英语辅导报高二版 04~05学年度第7期；版权归英语辅导报社所有，独家网络合作伙伴新浪教育，未经许可，不得以任何形式进行转载。)