(1) who引导的非限制性定语从句

如:Our guide，who was a French Canadian，was an excellent cook.

(2) whom引导的非限制性定语从句

关系代词whom用于指人，在句中作动词宾语和介词宾语，作介词宾语时，介词可位于句末。如：

Peter, whom you mey in London, is now back in Paris.

(3) whose引导的非限制性定语从句

whose是关系代词who的所有格形式，在从句中作定语。whose通常指人，也可指动物或无生命的事物。如：

The boy, whose father is an engineer, studies very hard.