关系副词

关系副词 where丶when 和 why 可以放在句中，也可以加在子句。在正式书写上，一般会用到「介系词 + which」的句型，用关系副词则是较普遍的用法。

引导关系子句的「介系词 + which」结构，较正式	使用关系副词的结构，较为普遍
That's the restaurant in which we met for the first time.	That's the restaurant where we met for the first time.
That picture was taken in the park at which I used to play.	That picture was taken in the park where I used to play.
I remember the day on which we first met.	I remember the day when we first met.
There was a very hot summer the year in which he was born.	There was a very hot summer the year when he was born.
Tell me the reason for which you came home late.	Tell me (the reason) why you came home late.
Do you want to know the reason for which he is angry with Sally?	Do you want to know (the reason) why he is angry with Sally?