英语语法请问什么是主语从句,表语从句,定语从句,非谓语,同位语从句,不定式,非限定性定语从句?请解释清楚一点,最好有例句

英语语法
请问什么是主语从句,表语从句,定语从句,非谓语,同位语从句,不定式,非限定性定语从句?请解释清楚一点,最好有例句

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、 几个共性问题：
1．连接方式
（1） 在由连词that, whether, if引导的名词性从句中,引导词在句中不做成分,在宾语从句和表语从句中,that可以省略.
（2） 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.
（3）在由连接副词when, where, why, how引导的名词性从句中,其连接副词在句中作状语.
2．whether和if的区别
（1）whether在引导的主语从句中可以置于句首,而if则不能.
（2）whether可以与or not连用,or not可以紧跟在whether之后,也可以置于从句末尾；if一般不能和or not连用.
（3）表语从句、同位语从句和介词宾语从句（即在系词be和介词之后）,只能用whether连接,而不用if.
（4）从句是否定式时,一般用if, whether很少用在否定式从句中.
例如：I don’t care if he doesn’t come . 如果他不来,我也不介意.
The problem is whether we can carry out the plan.
问题是我们是否能实施这项计划.
三、 主语从句
1．主语从句主要有三类：
（1） 由连词that引导的主语从句.
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） 用连接代词或连接副词if, whether 引导的主语从句.
例如： Which of them escaped from the prison is still a mystery.
他们哪一个是从监狱里逃跑的,仍然是个谜.
When they will come hasn’t been made pubic.
他们什么时候来还不知道.
Whether she is coming or not doesn’t matter too much.
她来不来都无关紧要.
（3） 用关系代词引导的主语从句.
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.
主语从句可以直接放在主语位置上,也可以用it作形式主语,
而将从句放在句末（尤其是当谓语较短时）.
例如：That light travels in straight lines is known to all.
光沿直线传播,这是众所周知的事.
=It is known to all that light travels in straight lines.
众所周知光沿直线传播.
When the plane is to take off has not been announced .
飞机何时起飞还没有宣布.
= It has not been announced when the plane is to take off.
还没有宣布飞机何时起飞.
当what引导的主语从句表示“…的东西”时,一般不用it作形式主语.
错:It is a book what he wants.
对:What he wants is a book. 他想要的是本书.
如果带主语从句的句子是疑问式,则必须用it作形式主语的结构.
例如：Has it been settled who will be sent to carry out the task ?
谁将被派去执行这项任务决定了吗 ?
3．固定用法和译法
（1） It is +名词+从句
It is a fact that… 事实是……
It is good news that … ……是好消息
It is a question that … ……是个问题
It is common knowledge that … ……是常识
类似的名词还有：a pity；a wonder；a good thing； no wonder； surprise等.
例如：It is a mystery to me how it all happened.
这一切是怎么发生的是个谜.
It is common knowledge that the whale is not a fish.
鲸鱼不是鱼,这是常识.
It is no surprise that Bob should have won the game.
鲍勃会赢得这场比赛,这不足为奇.
（2） It is +形容词+从句
It is necessary that … 有必要……
It is clear that … 很清楚……
It is likely that … 很可能……
It is important that … 重要的是……
类似的形容词还有：strange; natural; obvious; true; good; wonderful; possible; unlikely; quite; unusual; certain; evident; worth-while; surprising; interesting; astonishing, etc.
例如：It is obvious that conductors and insulators are both important in industry.
很明显导体和绝缘体在工业中都很重要.
It is doubtful whether she will be able to come.
她是否能来令人怀疑.
It was really astonishing that he refused to talk to you .
他拒绝和你说话真是令人惊讶.
It is essential that he should be here by the weekend .
周末之前,他应该到这里是必要的.
It seems obvious that we can not go on like this.
很明显我们不能这样下去了.
（3） It is +过去分词+从句
It is said that … 据说……
It is reported that … 据报道……
It has been proved that … 已证明……
It must be proved that… 必须指出……
类似的过去分词还有：known; estimated; expected; believed; thought; hoped; noted; discussed; required; decided; suggested; demanded; made clear; found out,etc.
例如：It is thought that he is the best player.
大家都认为他是最好的选手.
It is estimated that the vase is 2000 years old.
据估计这个花瓶有2000年的历史.
It is used to be thought that a new star must be due to a collision between two stars. 过去一直认为新星是由于两颗星星之间碰撞产生的.
It has not been made clear when the new road is to be opened to traffic.
还没弄清楚这条路将开始通车.
（4） It +不及物动词+从句
It seems that … 好像是……
It happened that… 碰巧……
It follows that … 由此可见……
It has turned out that … 结果是……
类似的不及物动词还有：seem, appear, occur, follow, happen, turn out, etc.
例如：It turned out that nobody remembered the address.
结果是无人记得那个地址.
It now appears that they are in urgent need of help.
看起来他们急需帮助.
It does not matter if I missed my train, because there is another later.
没有赶上这趟火车没有关系,稍晚还有一趟.
It happened that I saw him yesterday.
碰巧我昨天看见他了.
当“及物动词 + 宾语”较短时,也可用这种结构.
例如：It shocked me that Peter did not tell anybody where he was.
让我吃惊的是彼得没有告诉任何人他在哪里.
It does not interest me whether you go or not.
我对你去不去不感兴趣.
It +某些固定结构+ 主语从句.
例如：It doesn’t make too much difference （It doesn’t make any difference / It doesn’t alter the situation）,whether it rains or not . 下不下雨都没有多大关系.
It does not make any difference whether it rains or not .
下不下雨没什么分别.
It does not make the least difference to me what you do.
对我来说你做什么都无关紧要.
Is it of much consequence to you that Mr. Wang has failed to do it ? 王先生没有做成这件事对你有什么重要影响吗?
句子的表语是由一个句子充当的,那么这个充当表语的句子就叫做表语从句
The fact is that he was cheated.
这是个系表结构的句子,the fact是主语,谓语是系表结构,表语是that he was cheated,这个that引导的句子就是表语从句.
宾补和双宾的区别先看下面两个句子
They elected him president.
I sent him a telegram.
第一个句子里面的him是elect的宾语,而president则不是elect的宾语,它是补充说明宾语him的情况.
第二个句子里面的him 依然是send的宾语,而telegram也是send的宾语
定语从句（Attributive Clauses）在句中做定语,修饰一个名词或代词,被修饰的名词,词组或代词即先行词.定语从句通常出现在先行词之后,由关系词（关系代词或关系副词）引出.
非谓语动词主要包括不定式、动名词和现在分词.为了区分这三种不同的非谓语动词的用法和含义,我们将分别从三种非谓语动词在句子中做主语、宾语、宾语补足语、定语、状语、
表语以及一些特殊结构句型等角度来区分其用法和细微含义.
1．不定式和动名词作主语的区别
(1)动名词作主语通常表示抽象动作；而不定式作主语表示具体动作.
Smoking is prohibited(禁止)here．这里禁止抽烟.(抽象)
It is not very good for you to smoke so much．你抽这么多烟对你身体很不好.(具体)
(2)动名词作主语时,通常用以表示一件已知的事或经验.
不定式短语通常用来表示一件未完成的事或目的.
Climbing mountains is interesting．爬山很有趣.(经验)
Driving a car during the rush hour is tiring．在高峰时刻开车令人厌烦.(经验)
（3）不定式做主语,一般用it当形式主语,把作主语的不定式短语后置.
It took me only five minutes to finish the job.
2．不定式、动名词和分词作表语的区别
(1)不定式作表语
1)不定式作表语一般表示具体动作,特别是表示将来的动作.
To do two things at a time is to do neither．--次做两件事等于未做.
What I would suggest is to start work at once.我的建议是立刻开始干.
2）如果主语是不定式（表示条件）,表语也是不定式（表示结果）.
To see is to believe.百闻不如一见
To work means to earn a living．工作就是为了生活.
3)如果主语是以aim,duty,hope,idea,happiness,job,plan,problem,purpose,thing,wish等为中心的名词,或以what引导的名词性从句,不定式作表语是对主语起补充说明作用.
His wish is to buy a luxurious car in the near future．他的希望是在不远的将来买一辆豪华轿车.
The function of Louis Sullivan’s architecture was to provide large uninterrupted floor areas and to allow ample light into the interior.
The most important thing is to negotiate with them about the future of the plant．
(2)动名词作表语：动名词作表语,表示抽象的一般性的行为.
Our work is serving the people．我们的工作是为人民服务.
His hobby is collecting stamps．他的爱好是集邮.

(注)动名词作表语时与进行时态中的现在分词形式相同,但其所属结构迥异,进行时态说明动作是由主语完成的.动名词做表语,说明主语的性质或情况.
People cannot but feel puzzled,for they simply cannot understand how he could have made such a stupid mistake.
His victory in the final was no more convincing than I had expected．
(3)分词作表语
分词做表语有两种情况,一种是现在分词做表语,一种是过去分词做表语,这两者区别是考试中经常考到的地方.一般来说,表示心理状态的动词如excite,interest等都是及物动词,汉语意思不是“激动”,“高兴”,而是“使激动”、“使高兴”,因而现在分词应该是“令人激动的”、“令人高兴的”,过去分词则是“感到激动的”和“感到高兴的”.所以,凡表示“令人……的”都是-ing形式,凡是表示“感到……”都用-ed形式.换句话说,若人对……感兴趣,就是somebody is interested in...,若人/物本身有兴趣时,就是说sb./sth. is interesting.这类词常见的有：
interesting使人感到高兴--interested感到高兴的
exciting令人激动的--excited感到激动的
delighting令人高兴的--delighted感到高兴的
disappointing令人失望的--disappointed感到失望的
encouraging令人鼓舞的--encouraged感到鼓舞的
pleasing令人愉快的--pleased感到愉快的
puzzling令人费解的--puzzled感到费解的
satisfying令人满意的---satisfied感到满意的
surprising令人惊异的--surprised感到惊异的
worrying令人担心的--worried感到担心的
Travelling is interesting but tiring．旅行是有趣的,但是使人疲劳.
The pupils will get confused if they are made to learn too much．如果要学生学得太多,他们会感到糊涂的.
The argument is very convincing．他的论点很令人信服.
They were very excited at the news．听到这个消息,他们非常激动.
3．不定式和动名词作宾语的区别
英语中大多数动词既可跟不定式,也可跟动名词作直接宾语,但有些动词要求：
(1)不定式做宾语和宾语补足语
1)下面的动词要求不定式做宾语
attempt企图 enable能够 neglect忽视
afford负担得起 demand要求 long渴望
arrange安排 destine注定 mean意欲,打算
begin开始 expect期望 omit忽略,漏
appear似乎,显得 determine决定 manage设法
cease停止 hate憎恨,厌恶 pretend假装
ask问 dread害怕 need需要
agree同意
同位语从句用于对前面的名词作进一步解释,说明名词的具体内容.同位语从句一般由that引导,但也可以由whether 以及连接代词和连接副词引导.
同位语从句一般跟在名词fact, hope, idea, news, doubt, suggestion, information, opinion, decision, discovery, truth, promise, statement, problem, rule等的面.
They were all very much worried over the fact that you were sick. 对你生病这件事,他们都很焦虑.
Where did you get the idea that I could not come 你在哪儿听说我不能来?
I have no idea whether he'll come or not. 我不知道他是否来.
在一些表示建议、命令、要求的名词后的同位语从句中,谓语动词用should+动词原形表示,should可省略.
This is our only request that this (hould) be settled as soon as possible. 尽快解决这个问题,这是我们唯一的请求.
He made the suggestion that we go by train. 他建议我们坐火车去.
不定式是英语动词的一种形式.它在许多情况下可省略"to"它不同于汉语动词,汉语动词只有一种形式.如：我看书.她看书.但英语要说“看”必须根据主语的人称,动作发生的时间等确定其形式.如：1）I read a book. 2）She reads a book.1）句中的“read”
是一般现在时第一人称的动词定式.2）句中的“reads”是一般现在时第三人称单数的动词定式.
I want to read a book./She wants to read a book.
我想要看书.她想要看书.其中的“看”不易确定其形式.因为动作还未发生,因此称不定式.通俗的说,就是“不一定是什么形式”
请看例句： I want to go. 我想去
在这个句子中有两个动词,want 和 to go
want 是这个句子的主要动词,它随着主语的人称、数和时态而变化,如：He wants to go. We wanted to go.
to go 不管主语的数、人称和时态如何变化,它永远保持“to + 动词原型”的形式,to go 就是不定式.
动词不定式的基本形式是to + 动词原型,有时可以不带to, 动词不定式没有人称和数的变化,在句子中不能作谓语.
动词不定式仍保留动词的特点,即它可以有自己的宾语和状语.动词不定式和它的宾语或状语构成不定式短语.如：
I want to read the book. 我想读这本书.
book 是 read 的宾语,to read the book 为不定式短语.
1) 定语从句有限制性和非限制性两种.限制性定语从句是先行词不可缺少的部分,去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明,去掉了也不会影响主句的意思,它与主句之间通常用逗号分开,例如：
This is the house which we bought last month. 这是我们上个月买的那幢房子.（限制性）
The house, which we bought last month, is very nice.这幢房子很漂亮,是我们上个月买的.（非限制性）
2) 当先行词是专有名词或物主代词和指示代词所修饰时,其后的定语从句通常是非限制性的,例如：
Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了,他曾经是我的老师.
My house, which I bought last year, has got a lovely garden. 我去年买的的那幢房子带着个漂亮的花园.
This novel, which I have read three times, is very touching. 这本小说很动人,我已经读了三遍.
3) 非限制性定语从句还能将整个主句作为先行词, 对其进行修饰, 这时从句谓语动词要用第三人称单数,例如：
He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思,这使我心烦.
Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽,这就叫做蒸发.