初中英语语法总结(从句）
从句分为定语从句，状语从句和名词从句三大类。定语从句又分为限定性和非限定性从句两种，由关系代词或关系副词引导，修饰主句的某个成分。状语从句分为时间、结果、让步、原因、条件及行为方式状语从句。名词从句包括主语、宾语、表语和同位语从句及there be句型。
主系表结构、主谓（宾）结构、there be结构是英语的三大基本句式，无论一个句子有多长、多复杂，它总是属于这三大句式中的一种。
学习基本句式，句子成分是一个关键的概念，它是指句子的组成单位，不同的句式由不同的句子成分组成。如：主系表结构的成分有主语、系动词、表语；主谓（宾）结构的成分有主语、谓语、宾语；there be 结构的主要成分是主语。
英语中的句子成分主要有：主语、谓语、宾语、定语、状语、补语、同位语，等等。这些句子成分可以由单词、词组或句子充当，当这些成分由句子充当时，我们就有了相应的从句，如：充当主语成分的句子为主语从句，充当宾语成分的句子为宾语从句，等等。
英语从句三大类型
按一般说法，可分为三大类14种从句。
一，名词性从句
1主语从句Whether it’s right or not remains to be en。
2宾语从句I wonder whether it’s right or not。
3同位语从句This is a question whether it’s right or not。
4表语从句The question is whether it’s right or not。
二,定语从句
1限定性定语从句She is the student who can speak English well。
2非限定性定语从句She is the student， who can speak English well。
三，状语从句
1时间状语从句The fact will come out when he comes here。
2地点状语从句You can go wherever you like.
3原因状语从句Pay more attention to your lessons becau you are a student.
4方式状语从句He walks as if he were a king。
5目的状语从句She went to Japan so that she could learn Japane well.
6结果状语从句She went to Japan so that she learned Japane well。
7条件状语从句I will understand it if he tells me。
8让步状语从句He knows a lot though he is little。
1．定语从句
There are some old books in the box。
The boy dresd in blue is from America.
分清几个概念：先行词与关系代词/关系副词.先行词是指定语从句所修饰的中心词;关系代词主要有who， whom， who， which, that； 关系副词主要有 when， where， why.关系代词和关系副词有两个作用，一是连接主句和从句的作用，二是在定语从句中做成分。
⏹定语从句分为：限定性定语从句和非限定性定语从句， 限定性定语从句如果去掉会影响句子意义的完整性，非限定性定语从句即使去掉也不会影响句子意义的完整性，如:
July is the month when we have a lot of rain。
There are many plays （that) I’d like to e.
The meeting was put off, which surprid us a lot。
This note is left by Mary， who was here a moment ago。
1.非限定性定语从句,其作用为：对所修饰的成分作进一步的说明，它与主句用逗号隔开。此类从句省略后其余部分仍可成立。在非限定性定语从句中，which可代表前面的整个句子;
代表人时只能用who，whom，而不能用that；as也可用作关系代词.例如:
1。The telephone，as we know，was the invention of Alexander Graham Bell．
2。Franklin D．Roovelt，who died there on April 12，1945．
3。Living in a damp（潮湿的） hou for a long time is harmful to one’s health，which is known to everyone．
2.限定性定语从句中that可代表人和事,而which只代表事；二者在从句中作主语或宾语.that作宾语时常可省略，which则不能,而且其后的“不及物动词+介词’’中的介词不能省略。which作宾语时，先行词与which之间的介词不能省。例如：
1。The first doll that could say“mama”was invented in 1830．
2。The cond half of his voyage was by far the more dangerous part,during which he sailed round the Cape Horn合恩角．
代表all，anything，something，nothing，much等词时，用that而不用which，that作宾语可省略。例如:
1。I care anything that has something to do with it．
2.You'd better do something he prefers to do to plea him．
3.That is the last time we met each other．
4。I came across the woman you told me about yesterday．
who和whom引导的从句用来修饰人,分别作从句的主语和宾语。where是关系副词，用于表示地点的定语从句，而when用来表示时间。who是关系代词，修饰名词作定语。例如：
1。Henry Ford is the person who is most responsible for developing the idea of mass production．
2。The knee is the joint where the thigh bone meets the large bone of the lower leg．
3。The next morning， when she came down to breakfast ， Mary was beaming with the pleasure of a new，great discovery．
4。The visiting professor is a famous scientist who son studies in my department．
注意几点：that可替代who, whom（指人),也可替代which(指物）
who 既可指人又可指物
引导定语从句的关系代词紧跟介词做从句的宾语时，不用that，只用which// 不能用which,只能用that的情况…。
几个例子:Is she the girl that/who lls flowers?
The train that/which has just left is for Xi’an.
The people （who/that/whom） you were talking to were Russians。
The girl to whom I spoke is my cousin。
I have never met the boy who mother is a famous actress.
My book is on the table who legs are broken。
He went to China in 1945， when the War World was over。
Look， this is the hou where the writer was born。
The tool with which he is working is called a wrench（扳手).
2．状语从句
He swims fast.
Nervous， he opened the letter.
Legs broken， the soldier crawled back home。
She ud to stay up until midnight。
With a book in his hand, the teacher came in.
