who /whom 主语/宾语（可省） 指人 He who laughs last laughs best.

This is the boy (whom /who) you saw yesterday. which 主语/宾语（可省） 指物/事 A thing which was bitter to endure may be sweet to remember. that 主语/宾语（可省） 指物/事 The panda that is chosen Dragon Warrior is big and fat. 指人 They that know nothing fear nothing. whose 定语（某...的） 指人 Workers built shelters for survivors whose homes had been destroyed. 指物/事 The book whose cover is blue is mine. when 时间状语 时间 I'll never forget the day when the earthquake happened. where 地点状语 地点 This is the place where we first met. why 原因状语 原因 The reason why he was late was that he missed the bus.

2．只用that不用which的情况

当先行词是

　1）不定代词all, everything, anything, nothing, something, much, little, few, none, the one等时

　e.g. You can take any seat that is free.

　 We should do all that is useful to the people.

　2）被the only, the very, the same, the last等修饰时；

　　　e.g. It is the only thing that we can do.

　3）是或被序数词the first /second /third...所修饰时；

　 e.g. This is the first place that I want to visit.

　4）被形容词最高级所修饰时；

　 e.g. This is the most interesting book that I have ever read.

　5）同时指人和事/物时；

　 e.g. We talked about the things and persons that we were interested in.

6）主句以there be 开头时