学习一生why的定语从句用法
why的定语从句用法，同学们清楚了吗?如果不了解的话，为你解答，以下是为大家整理的why的定语从句用法，仅供参考，希望能够帮助大家！
why的定语从句用法
请分析下面两个简单句：
句①He wanted to know the reason.
句②I was late for the reason.
把句②变为句①的定语从句，句①中的the reasons做定语从句的先行词。因为the reason做介词for的宾语，先行词是the reason指物，在定语从句中介词for提前，用关系代词which替代the reason，the reason就不能在定语从句中出现了。由此得到句③He wanted to know the reason for which I was late.
注意：在定语从句中当先行词为the reason(s)，定语从句由for which引导时，可以用why代替for which。由此我们得到句⑤He wanted to know the reason why I was late.
请把下面两句话合并为一句，把第二句话变为第一句的定语从句
The reason is not very convincing.
He came for the reason.
→The reason why he came is not very convincing.
The reason for which he came is not very convincing.
when， where， why属于关系副词， 都在其引导的定语从句中充当状语， 其具体用法如下：
1. 关系副词 when引导定语从句(包括限定性定语从句和非限定性定语从句)修饰表示时间的先行词， 在定语从句中充当时间状语。例如： I still remember the day when I first met Jennifer.我仍然记得第一次见到詹妮弗的那一天。// Next month, when you’ll spend your summer holidays in your hometown, is approaching. 下个月即将来临， 届时你们将在家乡度暑假。
2. 关系副词where引导定语从句(包括限定性定语从句和非限定性定语从句)修饰表示地点的先行词， 在定语从句中充当地点状语。例如： This is the office where he worked. 这就是他工作过的办公室。// She is going to live in Ma***, where she has some close friends. 她要到澳门去定居， 在那里她有几个密友。
3. 关系副词why引导限定性定语从句修饰先行词reason， 在定语从句中充当原因状语。例如： I don’t know the reason why he came so late. 我不知道他来得那么晚的原因。// That is the reason why I don’t want to go. 那就是我不想去的理由。// He didn’t tell me the reason why he was so upset.他没有告诉我他为什么那样心烦意乱。
注意： 关系代词与关系副词之间并非毫无关联， 两者之间存在密切的`联系。在备考中尤其要注意以下几点：
1. 很多情况下关系副词用“介词+which/whom”来代替， 其中的介词由先行词或定语从句中谓语动词的形式来决定， 例如：
The day when I met the famous pop star was the greatest day of my life.
= The day on which I met the famous pop star was the greatest day of my life.见到这位著名歌星的那天是我一生中最重要的日子。
I shall never forget those years when I lived with her.
= I shall never forget those years during which I lived with her.
我将永远不会忘记我跟她生活的那些岁月。
This is a hall where the medical conference will be held.
= This is a hall in which the medical conference will be held.
这是礼堂， 医学会议将在此召开。
2. 并非先行词表示时间或地点时都分别用when或where来引导相应的定语从句， 若关系词在修饰表示时间或地点的先行词的定语从句中充当主语、 宾语等而不是状语时， 需用which或that引导相应的定语从句。例如： Do you still remember the days which/that we spent together in school? 你还记得我们一起在学校度过的那些日子吗?
先行词the days表时间， 但是其定语从句的引导词在定语从句中作宾语而不是状语， 因此不能用when而应该用which或that。
3. that有时可以代替定语从句中的关系副词when， where， why， 且that常可以省略， 例如： This is the time (when/that) he arrived. 这是他到达的时间。
[考题1] We are living in an age ____ many things are done on computer. (2003北京春)
A. which B. that C. whose D. when
[答案] D
[解析] 本题中下划线处所引导的限定性定语从句修饰表示时间的先行词age， 其引导词在该定语从句中充当时间状语， 因此只能填入关系副词when。
[考题2] The film brought the hours back to me ____ I was taken good care of in that far*9鄄away village. (2001)
A. until B. that C. when D. where
[答案] C
[解析] 本题中下划线处所引导的限定性定语从句修饰表示时间的先行词hours， 其引导词在该定语从句中充当时间状语， 因此只能填入关系副词when。
[考题3] It was an exciting moment for these football fans this year, ____ for the first time in years their team won the World Cup. (2000北京、 安徽春)
A. that B. while C. which D. when
[答案] D
[解析] 本题中下划线处所引导的非限定性定语从句修饰表示时间的先行词moment， 其引导词在该定语从句中充当时间状语， 因此只能填入关系副词when。
[考题4] After living in Paris for fifty years he returned to the small town ____ he grew up as a child. (1996)
A. which B. where C. that D. when
[答案] B
[解析] 本题中下划线处所引导的限定性定语从句修饰表示地点的先行词town， 其引导词在该定语从句中充当地点状语， 因此只能填入关系副词where。
[考题5] We will be shown around the city: schools, museums, and some other places, ____ other visitors seldom go. (2002北京)
A. what B. which C. where D. when
[答案] C
[解析] 本题中下划线处所引导的非限定性定语从句修饰表示地点的先行词some other places， 其引导词在该定语从句中充当地点状语， 因此只能填入关系副词where。
[考题6] I walked in our garden, ____ Tom and Jim were tying a big sign onto one of the trees. (2005辽宁)
A. which B. when C. where D. that
[答案] C
[解析] 本题中下划线处所引导的定语从句修饰表示地点的先行词garden并在该定语从句中充当地点状语， 因此只能填入关系副词where。
[考题7] We’re just trying to reach a point ____ both sides will sit down together and talk. (2006山东)
A. where B. that C. when D. which
[答案] A
[解析] point可以理解成地点、 位置， 其后面的定语从句中缺少地点状语， 因此下划线处只能填入引导词where