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。
The time when we got together finally arrived. 我们团聚的时刻终于到了。
October 1, 1949 was the day when the People's Republic of China was founded. 1949年10月1日是中华人民共和国成立的日子。
Do you remember the years when he lived in the countryside with his grandparents. 你还记得在农村和你祖父母一起生活的那些年吗？
2. where 指地点,在定语从句中作地点状语。
Shanghai is the city where I was born. 上海是我出生的城市。
The house where I lived ten years ago has been pulled down. 我十年前住的房子已经被拆掉了。
I visited the farm where a lot of cows were raised . 我参观了那个饲养了许多奶牛的农场。
Is this the place where they fought the enemy？ 这是他们当初打敌人的地方吗？
3. why 指原因,在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。
The reason why he was punished is unknown to us. 他受惩罚的原因我们都不知道。
I don't know the reason why he looks unhappy today. 我不知道他今天为什么看上去不愉快。
From the years when / in which he was going to primary school in the country he had known what he wanted to be when he grew up. 自从他在农村读小学时,他就已经知道长大后要做什么。
Great changes are taking place in the city where / in which they live. 他们生活的城市正发生巨大的变化。
The reason why / for which he refused the invitation is quite clear. 他为什么拒绝接受邀请的原因是十分明了的。
The teacher told me that Tom was the only person that I could depend on. 老师告诉我说汤姆是我唯一的可以依靠的人。
China is a country which has a long history. 中国是一个历史悠久的国家。
In the street I saw a man who was from Africa. 在街上我看到一个来自非洲的人。
His mother, who loves him very much, is strict with him. 他妈妈十分地爱他,对他要求很严格。
China, which was founded in 1949, is becoming more and more powerful. 中国是1949年成立的, 现在正变得越来越强大。
Last summer I visited the People's Great Hall, in which many important meetings are held every year. 去年夏天,我参观了人民大会堂,在那儿每年都要举行许多重要会议。
1. Her brother who is now a soldier always encourages her to go to college.
Her brother, who is now a soldier, always encourages her to go to college.
2. All the books that have pictures in them are well written.
All the books, which have pictures in them, are well written.