什么叫主语从句 什么叫宾语从句

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.
二：宾语从句的几个特征：1、引导词：what which whose when whether if where
2语序：宾语从句必须是用陈述语句。
如：I think that you must work harder.
宾语从句的引导词、连接词的区别、否定转移等现象。
(1)表达时间的几个句型：一般用when或者是what time：
What time will the train leave?
由于时刻都是固定的，也可以用一般现在时代替一般将来时：
What time does the train leave?
(2)时间的表达方式：8：19(nineteen past eight),(three to eight)，在时间的中间也可以加上分的单词(minutes)
(3)had better 动词原型。意思是提要求，建议。但是上下级不能用这种方式，因为语气太重：
You had better give up smoking .
(4)sb leave sth +地点
I left my book in my classroom yesterday.
(5)may I have your name(address\age)?一般询问对方的年龄、名字等，不要习惯以前的问法，这样很不礼貌，而是要采访上面的问法。以前的习惯是：how old are you? \what's your name?
(6)修饰名词的代词次序：类+名词：
this is a bridge.
This is a beautiful bridge

宾语从句
在句子中起宾语作用的从句叫做宾语从句.宾语从句分为三类:动词的宾语从句,介词的宾语从句和形容词的宾语从句.
可运用形式宾语it代替的宾语从句
①动词find,feel,consider,make,believe等后面有宾语补足语的时候,则需要用it做形式宾语而将that宾语从句后置.
I think it necessary that we take plenty of hot water every day .
我认为每天多喝开水是有必要的.
I feel it a pity that I haven’t been to the get-together.
我没去聚会,感觉非常遗憾.
I have made it a rule that I keep diaries.
我每天写日记成了习惯.
We all find it important that we (should) make a quick decision about this mater.
我们都认为对这件事马上做出决定很重要.
②有些动词带宾语从句时寻要在宾语与从句前加it
这类动词主要有:hate, take , owe, have, see to.
I hate it when they with their mouths full of food.
我讨厌他们满嘴食物时说话.
He will have it that our plan is really practical.
他会认为我们的计划确实可行.
I take it that you will agree with us.
我们认为你会同意我们的.
When you start the engine, you must see to it that car is in neutral.
开启发动机时, 一定要使汽车的离合器处于空挡位置.
③若宾语从句是wh-类,则不可用it代替
We all consider what you said to be unbelievable.
我们都认为你所说的是不可信的.
We discovered what we had learned to be valuable.
我们发现我们所学到的东西都是有用的.

宾语从句,一般来是这样:
1.时态倒移
2.一般可以用that引导
3.直接引语改为间接引语用宾语从句:
一:特殊疑问句改为陈述句语序
二:一般疑问句改时要加whether和if,表"是否"意

一般来说,学校里应该就教这个吧!
我也是初中生哦!比较了解吧!
主语从句与宾语从句同属名词性从句,二者有很多相似之处.我们已熟练掌握了宾语从句,因此了解二者的共性特征,掌握主语从句的难度将大大减轻.

　　(一)语序相同:都采用陈述语序.如:

　　I don't know whether he has come back.(宾从)

　　Whether he has come back is still unknown.(主从)(划线部分不可改为:Whether has he come back)

　　(二)从句与主句的时态搭配规则相同

　　1.主句用过去时,从句一般用过去时(如从句表示客观真理,可用现在时态).如:

　　I didn't know what food she bought.(宾从)

　　It was unknown what food she bought.(主从)

　　At that time people already knew that the earth is round.(宾从)

　　It was already known at that time that the earth is round.(主从)

　　2.主句为现在时,从句可根据需要选用各种时态.如:

　　I don't know when he came back/when he'll come back/whether he has come back.(宾从)

　　It is unknown when he came back / when he'll come back/whether he has come back.(主从)

　　(三)引导词相同,且在从句中的含义及句法功能相同

　　主语从句和宾语从句一样,引导词的选择都取决于该词在从句中的含义及充当的成分.各引导词功能如下:

　　(四)表示"建议"或"要求"时,从句都用虚拟语气.如:

　　They suggested that Tom (should) start as early as possible. (宾从)

　　It was suggested that Tom (should) start as early as possible. (主从)

　　二、查漏补缺,把握主语从句的独特性.

　　(一)注意主语从句与主句谓语动词的一致

　　1.主语从句多表示单一概念,因此主句谓语动词多用单数.如:

　　When and where we'll go isn't decided.

　　2.what引导的主语从句,根据表达含义的不同确定主句谓语动词的单复数.如:

　　What we need are books/is water.

　　(二)熟记"it作形式主语,主语从句后置"的常见句型结构

　　1.It + seem/appear/happen/chance等的适当形式+that从句.

　　2.It +系动词+过去分词+ that从句.

　　3.It +系动词+形容词+ that从句.

　　该句型中,如从句表示"应该做某事",从句需用虚拟语气.如:

　　It's necessary/important that you (should) be ready by 5 o'clock.

主语从句就是以一个句子作为主语使说明更完整，宾语从句是一个句子作为宾语使说明更完整

买本参考书好好看，主语从句和宾语从句高中还要学习