Unit 5 Nelson Mandela-a modern hero
语法探究
The Attributive Clause
一、关系副词
引导定语从句的关系副词有when , where或why等。when, where, why均在定语从句中作状语，在意义上相当于“介词 + which”结构，分别代替表示时间、地点或原因的先行词。
1. when 指时间，在定语从句中作时间状语。
I still remember the day when I first came to this school.
我仍然记得我第一次来到这所学校的那一天。(when = on which)
He came at a time when we needed him most.
他是在我们最需要他的时候来的。(when = at which)
2. where指地点，在定语从句中作地点状语。
I recently went back to the town where I was born.
我最近曾回过一次我出生的城市。(where = in which)
What's the name of the place where you spent your holiday?
你度假的那个地方叫什么名字？ (where = at which)
3. why 指原因，在限制性定语从句中作原因状语。
Please tell me the reason why you missed the plane.
请告诉我你误机的原因。(why = for which)
The reason why he was punished is unknown to us.
他受惩罚的原因我们都不知道。
