1. 定语从句的概念
2. 定语从句的关系词（关系代词：who, whom, which, that, whose；关系副词: when, where, why）
3. 关系词的辨别：
4. 定语从句注意事项：
a. 用 that不用which的情况：
当先行词是不定代词：all, little, few, much, something, anything, everything, nothing, none, some 等时
He did everything that he could to help us.
当先行词被all, every, no, some, any, little, much, the only, the very, the right, the last, just等修饰时
This is the only book the I want.
当先行词有序数词或最高级修饰时（或先行词本身就是序数词或形容词最高级时）
That is the most expensive hotel that we have ever stayed in.
当先行词既指人又指物时
The guests spoke highly of the children and their performances that they saw at the Children`s Palace.
当主语是以who 或 that开头的特殊疑问句时
Who is the person that is standing at the gate?
b. 用which不用that的情况
关系代词前有介词且指物时
The pen with which you are writing is mine.
先行词本身就是that时
What`s that which flashed in the sky just now.
c. 用who 不用that的情况
先行词是指人的不定代词， one，anyone，somebodym,those等时
Those who have good manners will be respected.
先行词指人并含有较长的后置定语或在被分割的定语从句中时
The boy was crying hard who lost his way while looking for his mother.
5. 定语从句中的主谓一致
One of + 名词复数
The ( only) one of + 名词复数
The very/ right +名词复数