英语的定语从句
一、与定语从句有关的概念
(1)定语从句：就是在复合句里充当定语的从句，它通常紧靠在所修饰的名词或代词后面。
(2)先行词：就是被定语从句修饰的名词或代词。
(3)关系词：引导定语从句的词叫关系词。关系词有关系代词who, whom, whose, which和that等；关系副词有when, where, why等。关系词不仅起连接作用，而且还代表先行词并在定语从句中担任某一句子成分，关系代词作主语、宾语、定语、表语等，关系副词作状语。如：
This is the book that my father bought me yesterday. 这就是我父亲昨天帮我买的那本书。
说明：句中修饰the book的that my father bought me yesterday就是定语从句；被定语从句所修饰的the book这是先行词；代表the book的关系代词that在定语从句中作bought的直接宾语。
The time when he arrives is not known. 他到达的时间还不知道。
说明：句中when he arrives是定语从句，被定语从句修饰的the time是先行词，关系副词when作时间状语。
二、关系代词的一般用法
先行词是人，在从句中作主语用who，作宾语用whom或who，作定语用whose；先行词是物，在定语从句中作主语或宾语都用which，作定语用of which或whose均可。在限制性定语从句中which, who, whom都可用that代替。关系代词作宾语时常被省略。
This is the man who helped me yesterday. 这就是昨天帮助我的那个人。(作主语)
The teacher (who/whom/that) you want to see is coming. 你要见的老师来了。(作see的宾语，可以省略)
I met a boy whose father was a astronaut. 我认识一位男孩，他的父亲是宇航员。(作定语)
Here is the coat which/that will be made to you. 这是一件做给你的衣服。（作主语）
This is the factory (which/that) we visited last year.这就是我们去年参观的那家工厂。(作visited的宾语，可以省略)
He has a book whose cover (=the cover of which) is very beautiful. 他有一本封面非常漂亮的书。
三、关系副词的一般用法
关系副词有when, where, why，在定语从句中作状语，分别表示时间、地点和原因。when的先行词通常是time, day, season, age, occasion等时间名词；where的先行词通常是place, city, town, village, house, case, situation, scenes等地点或情形名词；why的先行词只能是reason。关系副词when和where有时可用“介词＋which”代替，why可用for which代替。如：
There are occasions when (=on which) one must yield. 任何人都有不得不屈服的时候。
Beijing is the place where (=in which) I was born. 北京是我的出生地。
Is this the reason why (=for which) he refused our offer? 这就是他拒绝我们帮助他的理由吗？
注意：先行词虽然是时间或地点，但若在定语从句中作主语或宾语时，要用关系代词。
(1)The factory where his father worked has closed. 他父亲曾工作的那家工厂关闭了。(作状语)
比较：The factory which/that was built in 1978 has closed. 1978年建的那家工厂关闭了。(作主语)
(2) I’ll never fet the days when we lived together. 我永远也忘不了我们一起生活的那些日子。(作状语)
比较：I’ll never fet the days (that) we spent in Australia. 我永远也忘不了我们在澳大利亚度过的那些日子。(作及物动词spent的宾语)
(3) The reason (why) she was ill was that she had eaten bad meat. 她生病的原因是她吃了变质的肉。(作状语，用关系副词)
比较：The reason (that) he gave for his absence was obviously fabricated.他所说的缺席理由显然是编造的。(作gave的宾语，用关系代词)
四、只能用that引导的定语从句
(1)当先行词是指物的all, little, few, much, any, anything, everything, nothing, none, the one时，或先行词被all, little, few, much, any, every, no等修饰时。
All that can be done has been done. 能做的都已经做了。
He will tell you everything that he heard about it.他将告诉你他所听到的关于这件事的一切。
There is little work that is fit for you. 没什么工作适合你做。
I have eaten all the food that is left. 我把剩下的所有食物都吃了。
(2)先行词是序数词或最高级形容词时，或者先行词被序数词(包括last, next)、最高级形容词及the only, the very 等修饰时。
This is the first film that I have seen since I came here.这是我到这里后所看的第一场电影。
This is the best that has been used against pollution. 这是用来防止污染的最好办法。
This is the very book that I am looking for. 这正是我一直在寻找的那本书。
(3)先行词包括人和物时
They often talk about the people and the things that they are interested in. 他们常常谈论那些他们感兴趣的人和事。
(4)当主句是以who或which开头的疑问句时，为了避免重复，多用that引导。如：
Which is the house that caught fire last night? 昨晚失火的是那座房子？
Who is the lady that is playing the piano? 在弹钢琴的那位小姐是谁？
五、不能用that引导的定语从句
(1)在非限制性定语从句中，不以能用that引导。
Yesterday I met Mary, who seemed very excided. 昨天我碰到了玛丽，她显得非常兴奋。
(2)直接在介词后作宾语时，不能用that引导，要用whom, whose或which，且不能省略。
The house in which we live is not large. 我们住院的房子不大。
I know the young man with whom you live. 我认识和你住在一起的那个年青人。
但当介词放在从句的末尾时，可以用that替代which, who替代whom，也可以省略关系代词。如：
The house (which/that) we live in is not large. 我们住院的房子不大。
I know the man (whom/who/that) you live with. 我认识和你住在一起的那个人。
(3)当先行词是指人的all, any, few, one(s), anyone, everyone, people 等时，多用 who。如：
None so blind as those who won't see. 睁眼不看事实的人眼最瞎。
Anyone who is over sixteen is allowed in. 任何超过十六岁的人都允许进去。
I met someone who said he knew you. 我碰到一个人，他说认识你。
He who has a mind to beat his dog will easily find his stick. (谚)欲加之罪,何患无辞。
(4)当先行词与关系代词之间有较复杂的短语或从句隔开时
I was the only person in my office who was invited. 我是我们办公室里唯一受到邀请的人。
A new master will come tomorrow who will teach you German. 有位新校长明天来，他将教你们德语。
英语定语从句,简单点说!
定语从句中，关系代词：which that who whom whose
关系副词：where,when,why
所谓关系代词，就是在定语从句中代替先行词在从句中充当成分（充当主语，宾语或表语）
所谓关系副词，就是在定语从句中代替先行词做状语，when 在从句中做时间状语，when = in/at/during + which. '
where在从句中做地点状语 ，where = in/at/on/under + which .
why在从句中做原因状语 why = for which
来看你的例子
A. That is the school（ _____________we studied three years ago. ）
在这里，我打括号的为从句，此从句为定语从句，修饰先行词the school
是用关系代词还是关系副词， 首先要分析从句句子结构，看从句缺的什么：缺主语，宾语或是表语用关系代词；
缺状语用关系副词
看从句_____we studied three years ago. 从句里，主语为we，studied 为谓语动词，study可以做及物动词，也可做不及物动词，在这里不能说学习学校，只能说在学校里学习，所以可以看出，study在此句是不及物动词，不需要带宾语。从句里不缺主语，不需要宾语，又不是主系表结构，那么就不能用which（关系代词），所以只能用关系副词（where = in the school 在学校里）
That is the school __where 或者 in which___________we studied three years ago.
B. That is the school（ ____________ we built three years ago. ）
括号中为定语从此，还是修饰先行词the school
在分析从句结构，从句里说 we built..... 这里的“建设”为及物动词，也就是说要有宾语，可句中没给出来，说明 which 代替先行词在从句中充当宾语
你可以说我们建设学校，而不能说我们在学校里建
That is the school（ ___which/that_________ we built three years ago. ）
which /that代替先行词在从句里做built的宾语
A.I like the place （_____we visited last summer.）
B.I like the place （_____ we spent our holiday last summer. ）
A句，从句we visited last summer翻译为，“我们去年访问”，我们去年访问哪里？哪里为宾语，说明这个句子缺宾语，缺宾语就要用关系代词 用 which/that
B句，we spent our holiday last summer. 我们去年度假 。we 是主语， spent是宾语 our holiday 为spent的宾语 ，last summer是时间状语
我们说缺主语，宾语，或表语用关系代词。
而词句主谓宾齐全，所以不用关系代词，用关系副词where
我喜欢一个地方，我们去年在那里度假的地方
做这样的题 要看从句中缺什么成分：牢记 缺主语或宾语或表语 用关系代词，缺状语用关系副词
不知道看懂没
i'm sorry,感觉说的太罗嗦了....
在定语从句中,先行词group或band用who还是which
要看具体情况的，如果group或band 的内容都是人，并且你的定语从句中谓语的动作是强调人发出的，那么就用who.如果是单纯指那个group或band 的属性。。。等 就用which
如：the group are all men -=the members of the group are all men
the group is so harmonious 这个团队很和谐
定语从句 我们应该帮助那些需要帮助的人
We should help those who need help.