文档介绍：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，修饰主句某个成份。状语从句分为时间、结果、让步、原因、条件及行为方法状语从句。名词从句包含主语、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结构是英语三大基础句式，不管一个句子有多长、多复杂，它总是属于这三大句式中一个。
学习基础句式，句子成份是一个关键概念，它是指句子组成单位，不一样句式由不一样句子成份组成。如：主系表结构成份有主语、系动词、表语；主谓（宾）结构成份有主语、谓语、宾语；there be 结构关键成份是主语。
英语中句子成份关键有：主语、谓语、宾语、定语、状语、补语、同位语，等等。这些句子成份能够由单词、词组或句子充当，当这些成份由句子充当初，我们就有了对应从句，如：充当主语成份句子为主语从句，充当宾语成份句子为宾语从句，等等。
英语从句三大类型
按通常说法，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 seen.
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 because you are a student.
4方法状语从句He walks as if he were a king.
5目标状语从句She went to Japan so that she could learn Japanese well.
6结果状语从句She went to Japan so that she learned Japanese 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 dressed in blue is from America.
分清多个概念：先行词和关系代词/关系副词。先行词是指定语从句所修饰中心词；关系代词关键有who, whom, whose, which, that; 关系副词关键有 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作用，二是在定语从句中做成份。
定语从句分为：限定性定语从句和非限定性定语从句, 限定性定语从句假如去掉会影响句子意义完整性，非限定性定语从句即使去掉也不会影响句子意义完整性，如：
July is the month when we have a lot of rain.
There are many plays (that) I’d like to see.
The meeting was put off, which surprised us a lot.
This note is left by Mary, who was here a moment ago.
非限定性定语从句，其作用为：对所修饰成份作深入说明，它和主句用逗号隔开。这类从句省略后其它部分仍可成立。在非限定性定语从句中，which可代表前面整个句子；代表人时只能用who，whom，而不能用that；as也可用作关系代词。比如:
telephone，as we know，was the invention of Alexander Graham Bell．