概念说明：
主句：在含有定语从句的复合句中，除去定语从句后的部分，是主句。 (例句1中，This is the boy是主句。)
定语从句：相当于形容词，修饰主句中的一个名词或代词（有时修饰整个主句，相当于主句的一个定语。） (例句1中，who won the first prize in race是定语从句，修饰the boy。)
先行词：先行词就是被定语从句修饰的名词等，它总是出现在定语从句的前面。 (例句1中，the boy是先行词。)
关系词：关系词指用来引导定语从句的词，分为关系代词和关系副词。(例句中，who/that/which是关系代词, where是关系副词。)
关系词的三个作用
代指被修饰的先行词（例句1中，who指代的是前面的先行词boy）；
起着连接主句和从句的作用（例句1中，who起着连接主句和从句的桥梁作用）；
作定语从句的一个句子成分（例句1中，who在定语从句中是主语）。
举例如下：
◆指人时可以用who, 也可用that。
Do you know the boy who/that is my desk mate?
◆指物时可以用which,也可用that。
I like visiting places which/that are not far away.
◆whose可以指人也可以指物。
He was a painter whosepictures were not well- known in his life time.
The tree whose leaves are red was planted last year.
◆关系代词作宾语时可以省略。
I like the meal that/which / ( ) we had last night.
Do you know the boy who/whom/that/( ) we talked about just now?
注：（）表示关系代词省略
关系副词在从句中只能作状语。when 指时间，where指地点，why指原因，how不能作关系词。如：
1. We will put off the picnic until next week when the weather may be better.
2. He has reached the point where a change is needed.
3. That is no reasonwhy you should leave.
4. This is the wayhow I did it. (how不能作关系词)
解题技巧
① 确定关系词的种类：先看从句成分，缺必具成分，需用关系代词；不缺少必具性成分，用关系副词；另外注意关系形容词whose （of which）；
②确定先行词进而锁定关系词：结合语义和语法，找准先行词进而选出合适的关系词。注意：先行词未必紧挨着关系词。
跟踪练习
1.I live next door to a couple ______ children often make a lot of noise.
A. whose B. why C. where D. which
2.We will put off the picnic in the park until next week, ______ the weather may be better.
A. that B. where C. which D. when
3.Scientists have advanced many theories about why human beings cry tears, none of ______ has been proved.
A. whom B. which C. what D. that
4.Opposite is St. Paul’s Church, ______ you can hear some lovely music.
A. which B. that C. when D. where
5.The boss of the company is trying to create an easy atmosphere ______ his employees enjoy their work.
A. where B. which C. when D. who
6.Some experts think reading is the fundamental skill upon ______ school education depends.
A. it B. that C. whose D. which
7. China Today attracts a worldwide readership, ______ shows that more and more people all over the world want to learn about China.
A. who B. whom C. that D. which
8. As the smallest child of his family, Alex is always longing for the time ______ he should be able to be independent.
A. which B. where C. whom D. when
9.The books on the desk, ______ covers are shiny, are prizes for us.
A. which B. what C. whose D. that
10.I didn’t become a serious climber until the fifth grade, ______ I went up to rescue a kite that was stuck in the branches of a tree.
A. when B. where C. which D. why
11.The exact year ______ Angela and her family spent together in China was 2008.
A. when B. where C. why D. which
12.English is a language shared by several diverse cultures, ______ uses it differently.
A. all of which B. each of which C. all of them D. each of them
13. A company ______ profits from home markets are declining may seek opportunities abroad.
A. which B. whose C. who D. why
14.Please send us all the information ______ you have about the candidate for the position.
A. that B. which C. as D. what
15.“You can’t judge a book by its cover, ” ______ .
A. as the saying goes old B. goes as the old saying
C. as the old saying goes D. goes as old the saying
16.The children, ______ had played the whole day long, were worn out.
A. all of what B. all of which C. all of them D. all of whom
17.There is no simple answer, ______ is often the case in science.
A. as B. that C. when D. where
18.Happiness and success often come to those ______ are good at recognizing their own strengths.
A. whom B. who C. what D. which
19. Care of the soul is a gradual process ______ even the small details of life should be considered.
A. what B. in what C. which D. in which
20.I wish to thank Professor Smith, without ______ help I would never have got this far.
A. who B. whose C. whom D. which
21. By 16: 30, ______ was almost closing time, nearly all the paintings had been sold.
A. which B. when C. what D. that