第一章 句子的基本成分

1、二.主语从句引导词及其用法特点

连词that，不能省略，用于陈述句，在句子中不作成分；

连词whether，if不用于句首，用于一般疑问句，在句子中不作成分；

连接副词when，where，why，how，用于特殊疑问句，在从句中作状语；

连接代词who，whom，what，用于特殊疑问句，在从句中作主语，宾语或表语；

which，whose，用于特殊疑问句，在从句中作定语，后面接连词使用

2、三.it形式主语句型

(一)It is+形容词＋that主语从句

It is clear/obvious that...

It is possible/likely that...

It is natual that...

It is certain that...

（二）It is+过去分词+that主语从句

It is said that...

It is reported that...

It is generally believed that...

It has been found that...

It should be noted that...

（三）It＋不及物动词＋that主语从句

It appears/seems that...

It follows that...

It happens that...

It turns out that...

It comes about that...

（四）It is＋名词短语＋that主语从句

It is a pity that...

It is a fact that...

It is an honor that...

It is a shame that...

It is my belief that...

It is a good news that...

It is common knowledge that...

（五）其他结构

It dawns upon/on sb.that...

It occurs to sb.that...

It doesn't need to be bothered that...

It makes no difference that...

It is of litter consequence that...