什么是定语从句 状语从句 表语从句 宾语从句 怎样区分他们 尽量多举一些例子

主语从句
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.
宾语从句
置于动词、介词等词性后面起宾语作用的从句叫宾语从句.宾语从句的语序必须是陈述语序.谓语动词、介词、动词不定式,v.-ing形式后面都能带宾语从句.有些形容词（afraid,sure,glad等）之后也可以带宾语从句.
在复合句中作主句的宾语,引导词有：
连词：that (that 常可省略),whether, if
代词：who, whose, what ,which
副词：when ,where, how, why 等.
（一）that引导的宾语从句（在非正式场合that可以省略）
可跟that从句做宾语的动词有：
say, think, insist, wish, hope, demand, imagine, wonder, know, suppose, see, believe, agree, admit, deny, expect, explain, order, command, feel, dream, suggest, hear, mean, notice, prefer, request, require, propose, declare, report等.
例句：The boy believes that he will travel through space to other planets.
注意事项：当主句谓语动词是 think, believe, suppose, expect 等词,而宾语从句的意思是否定时,常把否定转移至主句表示.
例句：I don’t think it is right for him to treat you like that.
在以下情况中that不能省略
当句中的动词后接多于两个由that引导的宾语从句时,第一个that可省,但后面的that不可省.
例句：He said (that) you were too young to understand the matter and that he was asked not to tell you.
当主句的谓语动词与that宾语从句之间有插入语时,that一般不可省.
例句：Just then I noticed, for the first time, that our master was wearing his fine green coat and his black silk cap.
当that从句是双宾语中的直接宾语时,that不可省.
例句：I can’t tell him that his mother died.
注意事项：许多带复合宾语的句子,that引导的宾语从句经常移到句子后部,而用it作形式宾语.
例句：I find it necessary that we should do the homework on time.
（二）由whether,if 引导的宾语从句
由whether(if)引导的宾语从句,实际上是一般疑问句演变而来的.意思是“是否”.宾语从句要用陈述句语序.一般说来,在宾语从句中whether与if可以互换使用,但在特殊情况下if与whether是不能互换的.
例句：I wonder whether(if) they will come to our party.
只能用whether,不能用if引导的宾语从句
在带to的不定式前
例句：We decided whether to walk there.
在介词的后面
例句：I’m thinking of whether we should go to see the film.
在动词后面的宾语从句时
例句：We discussed whether we had a sports meeting next week
直接与or not连用时
例句：I can’t say whether or not thet can come on time.
只能用if不能用whether引导的宾语从句
if引导条件状语从句,意为“如果”
例句：The students will go on a picnic if it is sunny.
if引导否定概念的宾语从句时
例句：He asked if I didn’t come to school yesterday.
引导状语从句even if（即使）和as if（好象）时
例句：He talks as if he has known all about it.
（三）连接代词和连接副词引导的宾语从句
这样的宾语从句实际上是由特殊疑问句变化而来的,宾语从句要用陈述句语序.用于这种结构的动词常常是：see, say, tell, ask, answer, know, decide, show, find out, imagine, suggest, doubt, wonder, discover, understand, inform, advise等.
英语中的连接代词有：who,whom,whose,which,what,在句中担任主语、宾语、定语或者表语.
例句：Can you tell me whom you are waiting for?
英语中的连接副词有：when,where,why,how,在句中担任状语的成分.
例句：None of us knows where these new parts can be bought.
表语从句
1． 定义：用作表语的从句叫做表语从句.
2． 构成：关联词+简单句
3． 引导表语从句的关联词的种类：
(1) 从属连词that.如：
The trouble is that I have lost his address. 麻烦是我把他的地址丢了.
(2) 从属连词whether, as, as if.如：
He looked just as he had looked ten years before. 他看起来还与十年前一样.
The question is whether they will be able to help us. 问题是他们是否能帮我们.
注：从属连词if一般不用来引导表语从句,但as if却可引导表语从句,如：
All this was over twenty years ago, but it’s as if it was only yesterday.
这都是20多年前的事了,但宛如昨天一样.
能跟表语从句的谓语动词一般为系动词be, seem, look等.如：
It looked as if it was going to rain. 看起来天要下雨了.
(3)连接代词who, whom, whose, what, which, whoever, whatever, whichever
连接副词 where, when, how, why.
如：The problem is who we can get to replace her. 问题是我们能找到谁去替换她呢.
The question is how he did it. 问题是他是如何做此事的.
That was what she did this morning on reaching the attic. 那就是她今晨上了阁楼干的.
状语从句
状语从句(adverbial clause)在句中作状语,可修饰主句中的动词、形容词和副词等.状语从句由从属连词引导.状语从句可放在句首或句末.放在句首时,从句后面常用逗号；放在句末时,从句前面往往不用逗号.
When the plane arrived, some of the detectives were waiting inside the main building while others were waiting on the airfield.
当飞机抵达时,一部分侦探等在主楼里面,而另一部分则等在停机坪上.
When I came home, my wife was cooking dinner. 我回家时,妻子在做晚饭.
Though he was poor, he was happy. 虽然他很穷却很快乐.
If you ask him, he will help you. 如果你向他请求,他会帮助你.
Since you ask, I will tell you. 你既然问,我就告诉你.
I can't tell you when you won't listen. 既然你不想听,我就不告诉你了.
He stopped trying, when he might have succeeded next time. 他不再试了,其实他可能下一次就成功.
定语从句
定语从句是由关系代词和关系副词引导的从句,其作用是作定语修饰主句的某个成分,定语从句分为限定性和非限定性从句两种.
一、 限定性定语从句
1. that即可代表事物也可代表人,which代表事物；它们在从句中作主语或宾语,that在从句中作宾语时常可省略关系词,which在从句中作宾语则不能省略.而且,如果which在从句中作“不及物动词＋介词”的介词的宾语,注意介词不要丢掉,而且介词总是放在关系代词which的前边,但有的则放在它原来的位置
2. which作宾语时,根据先行词与定语从句之间的语义关系,先行词与which之间的介词不能丢
3. 代表物时多用which,但在带有下列词的句子中用that而不用which,这些词包括all, anything, much等,这时的that常被省略
4. who和whom引导的从句用来修饰人,分别作从句中的主语和宾语,whom作宾语时,要注意它可以作动词的宾语也可以作介词的宾语
5. where是关系副词,用来表示地点的定语从句
6. when引导定语从句表示时间
〔注〕值得一提的是,表示时间“time"一词的定语从句只用when引导,有时不用任何关系代词,当然也不用that引导
By the time you arrive in London, we will have stayed there for two weeks.
I still remember the first time I met her.
Each time he goes to besiness trip, he brings a lot of living necessities, such as towers, soap, toothbrush etc.
7. whose是关系代词,修饰名词作定语,相当于所修饰成分的前置所有格
8. 当从句的逻辑主语是some, any, no, somebody, anybody, nobody, something, anything, everything或nothing时,常用there is来引导
二、非限定性定语从句：非限定性定语从句的作用是对所修饰的成分作进一步说明,通常和主句间用逗号隔开,将从句拿掉后其他部分仍可成立
1. which引导的非限定性定语从句来说明前面整个句子的情况或主句的某一部分
2. 在引导限定性定语从句时,that有时相当于in which, at which, for which或at which
Attitudes towards daydreaming are changing in much the same way that(in which) attitudes towards night dreaming have changed. 人们对白日做梦的态度正在改变,这与人们对夜间做梦的看法的变化有非常相似之处.
I like the music for the very reason that(for which) he dislike it. 我出于某种原因喜欢这种音乐,而他恰恰与我相反.
We arrived the day that(on which) they left. 刚好我们到的那天他们走了.
3. 有时as也可用作关系代词
4. 在非限定性定语从句中,不能用that,而用who, whom代表人,用which代表事物