如题所述
引导主语从句的when, where, why作用有二:1,引起主语从句;2,在主语从句中做状语。例如:When you went there was known to us all.
引导定语从句的when, where ,why叫做关系副词,它们一定跟在一个名词的后面,并代替这个名词在定语从句中作状语。例如: This is the house where Lu Xun once lived.