when/where/why引导的定语从句的用法
when/where/why引导的定语从句的用法
when/where/why引导的定语从句
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 Macao, 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：
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
［考题1］ We are living in an age ____ many things are done on computer.
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 away village.
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.
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.
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.
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.
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.
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
拓展阅读
定语从句as的用法
一、用作连词的as
1. 引导时间状语从句，表示“当……的时候”，其用法与when和while类似。例如：As a child (When he was a child), she was sent to six different schools.此用法中as多表示从句与主句动作同时进行，意为“一边……一边……”，一般不与状态动词连用。例如：She sang songs as she did her homework.
as 还可以表示一动作紧接着另一动作发生，说明另一动作的结果，有“随着……”的含义。例如：As time went by, we found he was an honest man./As he grew older, he lost interest in everything except gardening.
例1 It wasn’t until nearly a month later________ I received the manager’s reply.
A. since B. when C. as D. that
解析：本题的as中与when一起作为干扰项，容易使考生往时间状语从句上思考，事实上本题是强调句，正确选项是D。
2. 引导原因状语从句，表示“由于，因为”，相当于because, 但通常置于句首。例如： As he is a qualified doctor, I trust his advice on medical matters.
例2 _____ modeling business is by no means easy to get into, the good model will always be in demand.
A. While B. Since C. As D. If
解析：本题中as干扰性很强，很多考生误以为是原因状语从句，但仔细分析不难发现正确答案应是A(while表示“只要”)。
3. 引导让步状语从句，通常可与although或though通用，但语序不同，although或though用于句首，as用于倒装结构。例如：Young as I am, I already know what career I want to follow. /Although(或Though)I am young, I already know what career I want to follow. as 表示让步用于倒装结构，通常将从句的表语、状语或动词前置。如果表语有冠词a/an, 需去掉。例如：Great scholar as he is, he is lacking in common sense./Much as I like you, I couldn’t live with you. 例3 _____ he has limited technical knowledge, the older worker has a lot of experience.
A. SinceB. Unless C. As D. Although
解析：as 虽然有引导让步状语从句用法，但本题不是倒装结构，故正确答案应是D。
4. 引导方式状语从句，表示“如，像”。例如：When in Rome, do as Romans do./Do to others as you would have others do to you.
例4 We wanted to get home before dark, but it didn’t quite ________ as planned.
A. make outB. turn out C. go onD. come up
解析：本题考查动词词组辨析，题干中的“as planned”给同学们提供了重要信息，答案选B。
5. 固定句型：“主句，as +be/do+主语”表示“也一样”。例如：She’s unusually tall, as are both her parents./He’s a doctor, as was his wife before she had children.
二、用作介词的as
1.表示“如，像”。例如：They got united as one man./She spoke of me as her dearest friend.
2.表示“作为、当作”。例如：As a League member, you should think more of others.
3.与某些动词搭配，表示“把……当作……”，如：look on…as…, regard…as…, treat…as…, consider…as…, think of…as…, see…as…等。其中consider…as…中的as可以省略。as与famous或known搭配，表示“作为……而出名”。
例5 Linda worked for the Minnesota Manufacturing and Mining Company, ________ as 3M.
A. knowingB. known C. being knownD. to be known
解析：如果熟悉be known as这一短语，运用有关非谓语动词的常识，可选出正确答案B。
三、用作关系代词的as
1. 引导限制性定语从句，先行词前通常有as, so, such, same等修饰语。例如：He will marry as pretty a girl as he can find./My hometown is no longer the same as it used to be./As many people as are present will be given a present.在此种用法中，同学们要注意与结果状语从句的区别。比如：A: The teacher asked us such a difficult question that none of us could answer it. B: The teacher asked us such a difficult question as none of us could answer.A句为结果状语从句，而B句则是定语从句。
2. 引导非限制性定语从句，用来指代整个主句(即先行句)，表示“这一事实，那一情况”。从句可以位于句首、句中或句末。例如：We stand when the national anthem is played, as is the custom.
例6 ______ I explained on the telephone, your request will be considered at the next meeting.
A. When B. After C. As D. Since
解析：根据句意，选项C是正确答案。as表现的正是本点所讲用法。
四、用作副词的as
修饰形容词或副词，表示程度，意为“同样地”。例如：He swims fast, but I swim just as fast. 但它通常构成表示比较的结构“asas”，“not asas”。此结构中第一个as是副词，第二个as是连词。否定结构中的副词as可以由so代替。asas possible /one can也属于此用法。例如：It is generally believed that teaching is as much an art as it is a science.
五、用在习语中的as
由as构成的习语很多，常见的有：as soon as “一就”，引导时间状语从句;as/so long as “只要”引导条件状语从句;as if/though “好像，仿佛”，引导方式状语从句或表语从句;as to/ as for “至于，就而言”;as much/many as“多达”;as/so far as “就的限度”;as a result，as a result of “(由于的)结果”;as a matter of fact“事实上”;as well “也、还”;A as well as B“不但A而且B”;as it is“照现状看，看样子”，等等。这些习语在高考中可能经常遇到，在高考题中有的作为正确选项，有的作为干扰项，有的出现在题干，值得同学们认真掌握。例如：
例9 I would like a job which pays more, but ______ I enjoy the work I’m doing at the moment.
A. in other wordsB. on the other hand C. for one thing D. as a matter of fact 解析：选项D极具干扰意义，但进一步研读会发现本题中的两个分句表达了一件事的两个对立面，故选B。
例10 ——People should stop using their cars and start using public transport. ——______. The roads are too crowded as it is.
A. All right B. Exactly C. Go aheadD. Fine
解析：本题选项中虽没有as内容，但题干中的as it is却是解题的关键信息，正确选项为B。
