名词性从句指充当名词成分的从句，下分很多类型，是英语学习的重点，可以说搞懂了名词性从句，你的英语水平就极大的提升了一个level，而主语从句则是名词性从句非常重要的一种类别，所以这次小编就为大家带来关于主语从句的讲解，快点来看看吧！

一. 概念：在句子中担当主语的从句就叫做主语从句，通常放在主句谓语动词之前或由形式主语it代替，而本身放在句子末尾。

主语从句使用陈述语序，其通常结构为“引导词 + 主语 + 谓语 + 其他成分", 但当连接代词同时充当从句主语时，其结构为“连接代词 + 谓语 + 其他成分”。

二. 引导词：

1. that引导

eg. That you are coming to London is the best news I have heard this long time.

2. whether引导

eg. Whether they would come to conference was a question.

3. 连接代词引导: who,whom, whose, what, which, whoever, whomever, whichever, whatever

eg. Whoever is top from wins the game when two matched players meet.

4. 连接副词引导: therefore, besides, otherwise, however, moreover, still, thus, meanwhile

eg. How this happended is not clear to anyone.

5. 关系代词型what引导

eg. What shoked me was that she never wash her own clothes.

三. 形式主语it:

1. 对关系代词型what引导的主语从句，可以使用形式主语。

eg. It is clear enough what he meant.

2. 如果句子是疑问句，则必须用带形式主语it的结构.

eg. Is it true that all of us need to to conference?

好了以上就是这次为大家带来的关于主语从句的知识点讲解，大家都学得怎么样呢？千万不要忘记之后的复习哦！