定语从句中关系副词有when, where,why, how等，其代替前面的先行词，在从句中有着时间状语，地点状语，原因状语的作用。另外也可用介词+which的结构。比如from which, of which, in which等。
1.在从句中作时间状语

A.I still remember clearly the day when I first left my parents.

我仍旧清晰地记得我第一次离开父母的那一天。（when 修饰the day）

B.Who knew the time when the last train came?

谁知道最后一列火车到来的时间。

C.From the year in which he was going to college he began to know a lot.

从他将要去上大学的那一年起，他懂了很多。

2.在从句中作地点状语
A.Chongqing is the city where she was born.
重庆市她出生的城市。

B.This place where I have lived three years will have a big change.

我已经生活了三年之久的地方将会有一个大的变化。

C.Great progress has been made about economics development in the city in which I had visited.

在我去过的这座城市经济发展已经取得了巨大的进展。

3.在从句中作原因状语
A.Perhaps, that`s the best way to reveal the reason why the expenditure of living has rose.
可能这是最好的方式揭示生活花费上涨了的原因。（这个句中why可以用for which来替换，从句可以写成”for which the expenditure of living has rose”）

B.I don`t understand the reason why Lisa dropped out in junior school.
我不明白为什么丽萨在中学辍学的原因。（同样的，该句从句可以改写成”for which Lisa dropped out in junior school”）

C.The way in which he overcame difficulties gave us much brainwaves.
他战胜困难的方法给了我们很多启发。