什么是主语从句,表语从句,他们的区别是什么

主谓宾,定状补.表语从句就是修饰名词的一个句子,一般THAT引导.
1． 定义：用作主语的从句叫做主语从句.
2． 构成：关联词+简单句
3． 引导主语从句的关联词有三类：
(1) 从属连词that.如：That they were in truth sisters was clear from the facial resemblance between them.
很明显,她们确是亲姐妹,她们的脸型很相似.
(2) 从属连词whether.如：
Whether he’ll come here isn’t clear.他是否会来这里还不清楚.
(3) 连接代词who,whom,whose,what,which,whoever,whatever,whichever
连接副词 where,when,how,why.如：
What she did is not yet known.她干了什么尚不清楚.
How this happened is not clear to anyone.这事怎样发生的,谁也不清楚.
Whoever comes is welcome.不论谁来都欢迎.
Wherever you are is my home ---- my only home.你所在的任何地方就是我的家----我唯一的家.