根据句中的谓语动词辨别就可以了
只是介词前置而已
也就是说前面的介词取决于主句中的动词
很简单
如
in which
The building in which he studied was very old.
实际上是study in the building将in前置
这句子可以分成两句
He studied in the building.
The building was very old.
限制性定语从句就是把这两个句子合成一句
同理 for which
The picture for which he paid $1,000 was once owned by a duke.
pay for 将 for前置