whose、of which和of whom都是定语从句中的引导词
of which 指物,of whom 指人,而whose既可指物又可指人 .所以指物的时候,可以用whose也可以用of which 代替；指人的时候可以用whose,当然可以用of whom 代替.
其实whose、of which和of whom的使用比较特殊,成分不是简单地主语宾语表语等,而是这个语中的一个名词所属.（就成分而言,和常规的只用which,who,whom或that 略有区别,因为常规的which,who,whom或that 可以较明确的指明它们在从句中的成分.比如 this is the book which i bought yesterday.which 做从句的宾语）
而且写出来,多是非限定性定语从句,即加一个“,”.
of whom ：i knew li ming,whose uncle is a teacher.
i knew li ming,the uncle of whom is a teacher.
源自 两个简单句或一个并列句
i knew li ming.his uncle is a teacher.
i knew li ming and his uncle is a teacher.
of which i saw the montain,whose top was covered with snow.
i saw the mountain,the top of which was covered with snow.
同样源自 两个简单句或一个并列句
i saw the mountain.the top of mountain was covered with snow.
i saw the mountain.and the top of it was covered with snow.
或i saw the mountain.and its top was covered by snow.