鲁达 
英文中一共有三大类从句
名词性从句
定语(形容词性)从句
状语(副词性)从句
啥是从句？
用一个句子才充当句中成分的功能就是从句。
先来看
名词性从句
一个句子做了名词的功能就是名词性从句。
陈述句+that 变成变形以后的名词放在整句话中位置的不同分为
1.主语从句
2.宾语从句
3.表语从句
4.同位语从句
eg:
1.That Lily is beautiful is a fact.
2.We know (that) Lily is beautiful.
3.my opinion is that Lily is beautiful.
4.The opinion that Lily is beautiful is right.
定语从句(形容词性从句)
关系代词在句中做了成分。
eg:
人
1.This is the man who saved my life.
2.This is the man whom I saved.
3.This is the man whose life was saved by me.
物
1.This is the book that I bought.
2.This is the book which is very popular.
3.You always work hard,as everyone knows.
状语从句(副词性从句)