由 when, where, why 引导的定语从句。 1. when(=介词+which )指时间，在定语从句中作时间状语 I still remember the day when I first came to the school. 2. where( =介词+which)指地点，在定语从句中作地点状语 Shanghai is the city where I was born. 3. why= for which指原因，在定语从句中作原因状语 1) Please tell me the reason why you missed the plane.