主语从句有几种形式
满意答案好评率：0% 主语从句(Subject Clause)
定义:如果一个句子在复合句中充当一个主语,那么这个句子就是主语从句.
第一部分：常规主语从句，即句子在复合句中充当一个主语
（1)引导主语从句连词有that,whether,who,what,whatever等
（2)连词位于句首不能省略
（3)主语从句大多数情况下视为单三,但也有例外,如例9
第二部分：为了防止句子头重脚轻，通常把形式主语it放在主语位置，真正主语搁置于句末
（1)以that 引出的主语从句,常以形式主语it引导. It is +形容词名词某些动词ed that 从句.
（2) 在有些that从句中要用虚拟语气 (should do should have done)
主语从句与宾语从句两者的用法和在句中的作用是不同的，下面从它们的各自用法，介绍
一．主语从句
主语从句 定义:在句子中担当主语的是一个从句,这个从句就叫做主语从句。
主语从句是在复合句中充当主语的从句，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。
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：
It is a pity that you didn’t go to see the film.
2. 用it 作形式主语的结构
(1) It is 名词从句
It is a fact that 事实是
It is an honor that 非常荣幸
It is common knowledge that 是常识
(2) it is 形容词从句
It is natural that 很自然
It is strange that奇怪的是
(3) it is 不及物动词从句
It seems that似乎
It happened that 碰巧
(4) it 过去分词从句
It is reported that 据报道
It has been proved that 已证实
3. 主语从句不可位于句首的五种情况
(1) if 引导的主语从句不可居于复合句句首。
(2) It is said , (reported) 结构中的主语从句不可提前。例如：
It is said that President Jingo will visit our school next week.
(3) It happens, It occurs 结构中的主语从句不可提前。例如：
It occurred to him that he failed in the examination.
(4) It doesn’t matter how/whether 结构中的主语从句不可提前。例如：
It doesn’t matter whether he is wrong or not.
(5) 含主语从句的复合句是疑问句时，主语从句不可提前。例如：
Is it likely that it will rain in the evening
4. What 与that 在引导主语从句时的区别
What 引导主语从句时在句时在从句中充当句子成分，如主语．宾语．表语，而that 则不然。例如：
What you said yesterday is right.
宾语从句怎么改？我要方法。。。
1 连接词 ①that（可省略）
②if/whether
③wh-
2 语序（陈述句）
3 时态 ①客观事实（一般时态）
②主句过去式（从句相应的过去时态）
③一般时态（不变）
4 人称转换
5 时间状语 例：today-that day
yesterday-the day before
tomorrow-the next day
英语复合句变简单句的几种方法
一、用too...to或enough to将含有so...that结构的复合句变为简单句。如：1.He is so young that he can’t go to school.→He is too young to go to school.或He is not old enough to go to school.2.He has so much money that he can buy a car.→He has enough money to buy a car.二、把及物动词引导的由陈述句变成的宾语从句变为“及物动词+动词不定式（短语）”结构，由此将复合句变为简单句。（剩余1410字）
改宾语从句
1.you should do the work alone.I told my daughter.要改为宾语从句
l told my dauther__she should do the work alone________________.
2.Where can l buy the dictionary?John asks.改为宾语从句
John wants to know___where he can buy the dictionary____________.
3.Where the party will be held has not been announced.(改为it做形式主语的主语从句）
It has not been announced where the party will be held.
4。What caused the accident was a mystery(同上）
It was a mystery what caused the accident.
5。That her hair is turning gray worries her.(同上）
It worries her that her hair is truning gray.
真心希望有帮助`(*∩_∩*)′