高中英语名词性从句和定语从句的语法总结（详细一点）

名词性从句是由if, whether, that 和各种疑问词充当连接词所引导的从句，其功同名词一样。

一．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。
2. 用it 作形式主语的结构
(1) It is ＋名词＋从句
(2) it is ＋形容词＋从句
(3) it is ＋不及物动词＋从句
(4) it ＋过去分词＋从句
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。
(3) It happens…, It occurs… 结构中的主语从句不可提前。
(4) It doesn’t matter how/whether …结构中的主语从句不可提前。
(5) 含主语从句的复合句是疑问句时，主语从句不可提前。
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。

定语从句也称为关系从句或形容词性从句，由关系代词（who, whom, whose, which, that）或关系副词（as, when, where, why）等引导。关系词除了起引导作用外，还在从句中指代前面的先行词，并在从句中担任一定的成分。
一、限定性定语从句和非限定性定语从句
定语从句就其与先行词的关系而言，可分为限定性定语从句和非限定性定语从句。限定性定语从句和先行词之间没有逗号，表示对先行词起修饰限制作用；而非限定性定语从句和先行词之间有逗号分开，是对先行词进行补充说明，相当于并列句。如：
He is the man who has strong personality. 他是个个性很强的人。（限定性定语从句）
My brother, who works abroad, is coming next week. 我哥哥在国外工作，他下周将回来。（非限定性定语从句）
注：1. 非限定性定语从句不能用that来引导，一般用which，as或who（指人）。用which或as引导时，既可以修饰主句的部分内容，也可修饰主句的全部内容。如：
He spoke confidently, which impressed me most. （which指代整个主句，在从句中作主语）
2. as引导的非限定性定语从句既可以放在主句之前，也可以放在主句之后，但which或who引导的非限定性定语从句不能放在主句之前。如：
　　As we all know, the moon is a satellite of the earth.
　　The large area is covered with thick snow, which affects people's life greatly.
3. 在限定性定语从句中，关系代词作宾语时可以省略；但在非限定性定语从句中，关系代词作宾语时不能省略。如：
The film (which) I saw last night is about a young teacher. (which可以省去)
She introduced me to her husband, whom I hadn’t met before. (whom不能省去)

二、通常只用关系代词that，不用 which，who或whom的几种情况
1. 当先行词是all, everything, nothing, something, anything, little, much, none, few等时。如：
All that you want are here.
2. 当先行词被all, no, some, any, every, a few, a little, much, only, very等修饰时。如：
There is no person that doesn’t make mistakes.
3. 当先行词被序数词或形容词最高级修饰时。如：
This is the best film that I have ever seen.
4. 当出现两个或两个以上的先行词，并同时兼指人和物时。如：
　We are talking about the people and countries that we have visited.
5. 当主句是以which 或 who 开头的特殊疑问句时。如：
　Who is the person that is standing over there?
6. 当定语从句为there be 句型时，关系代词只能用that，但经常可以省略。如：
　I know the difference (that) there is between you.
7. 当关系代词在从句中作表语时，常用that。如：
He does not seem to be the man that he was. 他似乎和过去不一样了。

三、as 与其他词连用引导的定语从句
as 引导定语从句时，可指人也可指物，通常与the same，such，so等连用，形式为：the same… as，such… as，as …as，so… as。As在定语从句中可作主语、宾语、表语等。如：
She knew he felt just the same as she did. 她知道他的感觉与她自己的一样。(as代替事，作宾语)
I lend you such books as will interest you. 我借给你使你感兴趣的书。(as代替物，作主语)
注：the same… as 和the same… that的用法不同。as引导的定语从句表示其内容与主句所讲的事物“相似”，指同类事物；that引导的定语从句表示其内容与主句所讲的事物是“同一个”，指同一事物。如：
This is the same pen as I lost yesterday. 这和我昨天丢的笔一样。（类似的笔）
This is the same pen that I lost yesterday. 这支笔就是我昨天丢的那支。（同一支笔）

四、“介词+关系代词”引导的定语从句
在“介词+which/whom”结构中，介词的选择取决于三种情况：
1．定语从句中谓语动词或表语的搭配。如：
This is the college in which I am studying.
He is the man about whom we are talking.
2．先行词与介词的习惯搭配。如：
The speed at which the machine operates is shown on the meter. 仪表上显示出这台机器运转的速度。
3．当定语从句为最高级时只能用of which; 否则用其他介词。如：
　 I have five dictionaries of which Longman Dictionary is the best.
　I have five dictionaries among which Longman Dictionary is published in UK.
注：不可拆分的动词短语介词不能提前，如put up with；有的短语可能有不同的介词搭配，此时需要根据上下文来确定。如：be familiar with/to，compare with/to等。
有时为表意清楚，还可以在关系副词where/ when前加介词from, to等。如：
China is the birthplace of kites, from where kite flying spread to Japan, Korea, Thailand and India. 中国是风筝的故乡，从这里，放风筝的运动传到了日本、韩国、泰国和印度。

1.主语从句
1）主语从句可直接位于主语的位置，如果从句较长，谓语又较短，可用it作形式主语，而将从句放在句末。常见的句型有：
*It is a fact\a pity\a question\good news that...
*It seems\appears\happened\has turned out that...
*It is clear\important\likely\possible that...
*It is said\reported\estimated\has been proved that...
It is said that comic books create a connection between people of the same generation.
It seems that the performance is very useful.

2)what引导的主语从句表示“...的东西时”，一般不用it作形式主语。
What we lack is experience.

3)what,who,when,why,whether等词含有各自的疑问意义，但它们引导的主语从句，都用陈述语序。
How the plan is to be carried out should be discussed again.
I did know why I felt like crying.

2.宾语从句
1）宾语从句可位于及物动词、介词和某些形容词后。连词that常可省略。介词后一般接疑问词引导的宾语从句。in that(因为),except that(除了),but that(只是）已构成固定搭配，其他介词后一般不接that引导的宾语从句。
*I promised that I would change the situation.
*All this is different from what American young people would say about friendship.
*He is certain that watching so much television is not good for children.
*This article is well-written except that it is a bit too long.

2)宾语从句后如有宾补，要用形式宾语it来代替，而把宾语从句移至宾补之后。
He has made it clear that he would not change his mind.

3)在think,believe,suppose,expect等动词后的宾语从句中，如果谓语是否定的，一般将否定词移至主句谓语上，宾语从句则变成肯定形式。
He didn't think that the money was well spent.

3.表语从句
表语从句出现在结构为“主语+系动词+表语从句”的句子中。表语从句除可用that,what,when,why,whether,how等引导外，还可由because,as if(though)等引导。that常可省略。如主句主语为reason,只能用that引导表语从句，不可用because.
Perhaps the most important thing to remember is that there is no one common type of life in America.

The reason why so many people died there is that there were not enough food supplies.

It looks as if successful international cultural communication will make the world smaller.

4.同位语从句
同位语从句用于对前面出现的名词作进一步说明，一般用连词that引导，由于先行名词的意义不同，也可用whether,who,when,where,what,why,how等引导。常见的先行名词有fact,idea,belief,news,hope,conclusion,evidence,suggestion,order,problem,report,decision.有时由于谓语较短，将同位语从句位于谓语之后。

She finally made the decision that she would join the fashion show.

I had no idea how many books I could borrow at a time.

The news came that their team had won the championship.
5.定语从句
定语从句所修饰的先行词可以是名词或代词，也可以是一个句子。定语从句通常位于先行词之后，由关系代词或关系副词引导。

*限制性定语从句
限制性定语从句修饰先行词，对先行词起修饰作用，紧接先行词之后，无逗号，若省去，原句意思不完整。引导定语从句的关系代词有who,whom,whose,which,that等。who,whom,whose用于指人，whose有时也可指物，相当于of which；which用于指物；that既可指人也可指物，但只用于限制性定语从句中。关系代词除了引导定语从句，替代先行词外，还在从句中担任主语、宾语、定语等。
The computers and cables which make up the Internet are owned by people and organizations.

Those who live alone or who are sick may have trouble in getting close to other people.

The girl whose parents died in an accident is living with her grandmother.

1)当先行词是all,anything,everything,something,nothing等不定代词或先行词前有first,last,any,few,much,some,no,only以及形容词最高级修饰时，只能用关系代词that引导从句。
That is all that I've heard from him.

He's the first person that I'm going to interview this afternoon.

2)关系代词的省略
在从句中作宾语的关系代词常可省略。关系代词紧跟介词，作介词宾语时不可用that，只可用which或whom引导从句，并且不可省略，但当介词位于宾语从句句末时，作为介词宾语的关系代词仍可用that，也可省略。
This is one of those things with which we have to put up.

This is one of those things (which\that) we have to put up with.

3)引导定语从句的关系副词有when,where,why等。关系副词在从句中作状语，意义上相当于一个“介词+which”的结构。
Even in comic books where(=in which) there are no words,the stories are fully expressed through the drawings.

No one knows the reason why(=for which) he was so angry that day.

5.定语从句
*非限制性定语从句
非限制性定语从句既可修饰先行词，也可修饰整个主句，起补充说明作用，与主句之间有逗号隔开，若省去，原句意思不受影响。不可用that引导非限制性定语从句。关系词不可省略。

Every object has a gravitational pull,which is rather like magnetism.

*“介词+which\whom\whose”引导的定语从句
“介词+which\whom\whose”可引导限制性定语从句，也可引导非限制性定语从句，该结构中介词的选择取决于从句谓语动词的固定搭配，或先行词的习惯搭配。

This is the computer on which he spent all his savings

It is written by a person with whom we are all familiar.

*as引导的定语从句
as引导的定语从句主要用于“such...as”及“the same...as”的结构中，代替先行词是人或物的名词。as引导非限制性定语从句时，代替整个主句，从句可位于主句之前、之后或中间。

These are not such problems as can be easily solved.(as代替先行词problems)

As is mentioned above,no single company or group can control what happens on the Internet.(as代替主语)

名词性从句

名词性从句就是在句子中充当名词功能的以相关从属连词引导的从句，包括主语从句、宾语从句、表语从句和同位语从句四种。
1．主语从句：以连词 that what whom whose what which whoever whatever whichever where when how why 引导，在句子中充当主语。
例：What she said is not yet known.
How this happened is not clear to anyone.
Whoever comes is welcome.
That she will do well is her exam is certain.（It is certain that she will do well in her exam.）
注：it 为形式主语，
2．宾语从句：以连词 that who whom whose what 等引导，在句子中充当宾语。
例：He told us that he felt ill.
Everybody knows what happened.
I doubt whether he will succeed.
I wonder what he is writing about.
3．表语从句：以 that whether who whom whoever when where when 等引导，在句子中充当表语。
例：The trouble is that I lost his address.
The question is whether they will be able to help us.
That was what she did this morning.
This is why we puts off the sports meeting.
4．同位语从句：同位语从句有自己的先行词，它跟定语从句很相似，先行词包含从句中所含内容，从句不起修饰作用。我们将在学习定语从句时，在加以详细比较，多用在连词what 引导。（不用which，此外还可用whether who where 等也可以引导。在这章中我们着重学习that whether 引导的同位语从句，引导同位语从句的先行词常用的有：fact news idea whether reply promise truth report remark 等。
例：I heard the news that the Chinese football team defeated the Japanese team
last night.
I have no idea whether he will come or not.
They were all much worried over the fact that you were sick.