身放在句子末尾。

1. It 作形式主语和it引导强调句的比较

It 作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。而it引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词that。被强调部分指人是也可用who/whom。例如：

1).It is a pity that you didn''t go to see the film.

2).It doesn''t interest me whether you succeed or not.

3).It is in the morning that the murder took place.

4).It is John that broke the window.

必背

用形式主语it引导的主语从句相当多，有些已形成固定的语法和译法。常见的有：

It is said that... 据说 It is reported that... 据报导

It is well known that... 众所周知 It is announced that... 据宣布

It is believed that... 人们相信 It is thought that... 人们认为

It is understood that... 自不待言 It must be pointed out that... 必须指出

It must be admitted that... 必须承认

2.主语从句的语序

主语从句要求使用陈述句语序，而非一般疑问句语序。如：

What surprised me most was that the little girl could play the violin so well.

使我感到惊讶的是这个小女孩的小提琴拉得太好了。

How he was successful is still a puzzle.

他是如何成功的仍然是个谜。

3. 连接词的选用

（1）that和what的选用

that和what都可引导主语从句。what除起连接作用外，还在名词性从句中充当某些成分，可作从句的主语、宾语或表语。而that在名词性从句中不充当任何成分，无词义，只起连接词作用。如：

What he wants is a book. 他想要的是一本书。

That light travels in straight lines is known to all. 众所周知，光线沿直线运行。

（2）if和whether的选用

引导主语从句，不能用if，只能用whether。如：

Whether we will hold a party in the open air tomorrow depends on the weather.

我们明天是否在户外开晚会要看天气而定。

（3）其它连接代词和副词的选用

根据主语从句的具体意义，正确的选择who, which, when, where, why, how等连接词，这些连接词既有疑问含义，又起连接作用，同时在从句中充当各种成分。如：

When we shall hold our sports meet is not decided. 我们何时举行运动会还没有决定。

Who broke the glass yesterday is not clear. 还不清楚昨天谁打破了玻璃。

Which car you will choose to buy makes no difference. 你决定买哪一辆车都不会有任何区别。

二．宾语从句

在复合句中用作宾语的从句叫做宾语从句。

1. 宾语从句常由that引导，在口语中常省略。当主句中谓语动词是现在或将来时态时，从句中谓语动词不受主句中谓语动词时态的影响，按需要可以使用任何时态。如：

She says (that) she works from Monday to Friday. 从句是一般现在时

She says (that) she will leave a message on his desk. 从句是一般将来时