你说的是主语从句主语从句
一、概述：在句子中起名词作用的各种从句统称为名词性从句.根据它们在句中的语法作用,这类从句又可分为主语从句、同位语从句、表语从句和宾语从句.
二.主语从句主要有三类：
（1） 由连词that引导的主语从句:引导词that无含义,在句中不做成分,不可以省.
例如：That you will win the medal seems unlikely.
你想获得奖牌看起来是不可能的.
That you are so indifferent bothers me.
你如此冷淡使我很烦恼.
That she survived the accident is a miracle.
她在事故中幸免于难简直是奇迹.
（2） 用连词 whether 引导的主语从句:whether有含义(是否),在句中不做成分,不可以省.例如：Whether she is coming or not doesn’t matter too much.
她来不来都无关紧要.
（3） 用连接代词引导的主语从句(在由连接代词who,whose,whom,which,what,whoever,whomever,whichever,whatever引导的名词性从句中,其连接代词在句中起名词性作用,担当一定成分).
例如：What you need is more practice.
你所需要的是更多的训练.
What I want to know is this.我想知道的就是这事.
Whatever we do is to serve the people.
我们无论做什么都是为人民服务.（4）用连接副词when,where,why,how引导的名词性从句(其连接副词有含义,在句中作状语.)eg:Where we should leave it is a problem.When they will come hasn’t been made pubic.
他们什么时候来还不知道.that引导从句有：
1.that引导的主语从句,不能省that
that引导的主语从句既可以放在句首也可以放在句末,在实际应用中我们常常采用it形式主语的形式.
例句：That he passed the English test is true.千真万确,他通过了英语考试.
→It is true that he passed the English test.
2.that引导的宾语从句
that常用来引导宾语从句,通常that可以省略.
例句：He has told me that he will go to Shanghai tomorrow.他已经告诉我他明天要去上海.
宾语从句的引导词除that 之外,还可以由连接代词(what ,which,who)和连接副词(when,where,how) 等来引导.例如:
1.Do you know what he has said
2.I don't know when we arrived.
3.that引导的表语从句,不能省
基本结构：主语 + 系动词 + that从句
例句：The fact is that we have lost the game.事实是我们已经输了这场比赛.
4.同位语从句通常由that引导,不能省
例句：The news that we won the game is exciting.
我们赢得这场比赛的消息令人激动.
5.用that引导定语从句的情况.如果that 在定语从句中充当宾语,that可以省
在不定代词,如：anything,nothing,something,the one,all,much,few,any,little等作先行词时,只用that,不用which.
例句：There is nothing that we can use.
这里没什么我们可用的东西.累死我啦