1.先行词为不定代词/被其修饰时(All，Anything，Nothing，Everything，Little，Few，Much，Any，The one)

　　eg.The only thing we can do is to give some money.

2.先行词前有形容词最高级修饰/是形容词最高级时

　　eg.The film is the most interesting that I have ever seen.

3.先行词是序数词/被序数词修饰时

　　eg.Tom is always the first that comes to the classroom.

4.先行词既指人又指物时

　　eg.The bike and its rider that had run over an old man were taken to the police station.

5.主句是以疑问词Who，Which开头的特殊疑问句

　　eg.Which is the bike that you lost?

6.有两个定语从句，其中一个关系代词已用过Which时

　　eg.Edison built up a factory which produced things that had never been seen before.

7.先行词被The only，the very，the lost，the same修饰

1.引导非限定性定语从句(前有,)

　　eg.Jim passed the driving test,which surprised everybody in the office.

2.关系代词前有介词

　　eg.I was put in a position in which I had to accept I was less important.

3.有两个定语从句，其中一个已用That

　　eg.Let me show you the novel that I borrowed from the library which was newly open to us.

1.Such+n.+as+定语从句

　　eg.We invited all such people as were likely to come.

2.Such…that+结果状语从句

　　eg.He is such a good boy that(连词不做成分) everyone likes him.

3.The same…as(表两物相似)

　　eg.This is the same knife as(宾语) I lost yesterday.

　　eg.She is just the same person as(表语) she used to be.

4.The same……that(表两物为同一物)

　　eg.This is the same knife that I lost yesterday.

5.The same也可与Where/when连用

　　eg.This is the same place where we had the party that day.

6.As引导状语从句或定语从句，不能引导名词性从句。As引导让步状语从句，译为“尽管”，引起倒装。

1.As引导的从句位于主句前/中/后均可，意为“正如”，“正像”，“和……一样”。放句首时，先行词为整个句子。

　　eg.As is reported in the newspaper,talks between the two countries are making progress.

2.固定结构

As we all know，as is known(to all)，as is/was reported，as is/was expected，as often happens，as you see， as can be seen， as we expect，as often the case，as I can remember，as has been said before.

　　eg.The earth is round,as is know.

3.未预料的，用Which，不用As

　　eg.Our team lost the game,which was unexpect.

预料到的，用As/which

　　eg.Our team won the game was expected.

4.先行词是Way(方式状语)时定语从句引导词(不用how)可为in which/that/省略

　　eg.I don't like the way in which/that/省略 you speak to her.

1.先行词为表示地点的名词时，在从句中作地点状语，相当于介词(in/on/at/to)+which

2.先行词为表示某人/物的形势(Situation)，某事发展的阶段(stage)，或表达某物的某个方面，以及point/atmosphere/language/activity等

　　eg.I got the stage where I wasn't coping(cope，应付) any more.

　　eg.For deaf dancers,dance is an activity where sight matters more than hearing.

3.特例

　　Tom stood at the top of the hill with his father,from where he could get a better view of the town.

1.定语从句：修饰、限定名词或代词，名词或代词必充当成分

2.同位语从句：解释说明其内容，抽象名词在同位语从句中不充当任何成分

1.限定性定语从句：修饰限制，联系更紧密

2.非限定性定语从句：补充说明