中考定语从句讲解定语从句请看下面的句子：（一）概念:定语从句：在复合句中修饰名词或代词的句子，叫定语从句。
先行词：被定语从句修饰的词叫先行词。
关系词：引导定语从句的词叫关系词。
（二）定语从句的分类Ⅰ、限定性定语从句：从句不可少，没有它，先行词的意思不明确，主句也不完整。
与先行词之间不用逗号。
e.g:This is the book that/which I want.Ⅱ、非限定性定语从句：是对先行词的补充说明，没有它不会影响先行词或主句意思的完整性。
从句一般用逗号同主句分开。
e.g:Mr. Green，who is watching TV，is my uncle.（三）(限定性)定语从句的结构Mary is a girl who has long hair.先行词关系词定语从句关系代词关系副词which, who, whom,whose, that where, when, why（四）定语从句的实质：二句合一（合并条件：人物先行在句一，又占句二一席地）Mary is a girl.合并为一个句子She has long hair.定语从句四部曲：1、写：两句（主干+定语从句）2、找：相同部分——先行词3、换：关系词（人or物）4、连：主句+从句Mary is a girl。
Mary has long hair.——Mary is a girl who/that has long hair.请把下列句子二句合一1. I like the book.The book is on the desk.2.This is the man . The man helped me .3.The doctor is in the that room. I am looking for the doctor.（五）定语从句关系词的确定:(先行词决定关系词)● a.先行词的分类● b.先行词在从句中充当的成分1.先行词做主语人：who/that物：which/that2.先行词做宾语人：who/whom/that物：which/that3.先行词做定语人：whose物：whose/of which4.先行词做状语：w h e n,w h e r e,w h y●who /that作定语从句的主语或宾语.The man who/that is speaking at the meeting is a worker.做题思路：先分解——分析——再合并The man is a worker.The man is speaking at the meeting.●Whom /that作定语从句的宾语The woman（whom/that) they wanted to visit is a teacher.分解The woman is a teacher.They wanted to visit the woman.注意: 关系代词作动词宾语时可省略.解题时，首先要结合选项对题干进行整体感知，确定定语从句的位置;根据定语从句中所缺少的句子成分，分析先行词逻辑上在定语从句中的成分，继而选出正确的选项。
例如：Can you tell me the name of the factory ________ you visited last week?A. whatB. whereC. /D. when简析：本题定语从句的主语、谓语、时间状语已具备，而visit 是个及物动词，从语义上分析，factory 作visit 的宾语。
故只能选C (引导词在定语从句中作宾语时可以省略)。
●whose 作定语从句的定语.I know the girl whose mother is a teacher.分解I know the girl.The girl’s mother is a teacher.作定语小结：关系词判断步骤●首先，要辨别出先行词。
如果先行词是指人,关系词可能就用who, that whom, whose。
如果先行词指物,关系词可能用which或that先行词主语宾语定语人who, that who(m), that whose物which,that which, that whose,of which巩固练习：用适当代关系词填空1. I have a friend ________ likes listening to classical music.2. Yesterday Emily was wearing the new dress __________ I gave her.3. The man ______ leg broke in a match used to be a football player.（六）只能用that,不能用which的情况：(1)先行词为all, everything，anything，nothing, something, nothing ,few, little, much, the one 等不定代词时；(2)先行词被形容词最高级所修饰或被the only, the very, the last, any, few, little , no, all, one of 等修饰时：(3)先行词为数词或被序数词（含last)修饰时。
（4）先行词是并列词组既有人又有物时。
(5)在以who, which开头的句子中为了避免重复。
口诀：不定代词这一伙，全用that准没错先行词前有修饰，千万不能用which.请在以下例句中体会以上规则：1. Here is something that I will tell you.2.We haven’t got much that we can offer you.3. Is it the one that you want ?4.This is the most interesting story that I have ever heard.5. I can remember well the persons and some pictures that I see.6.Which is the bike that you lost?7.Who is the woman that was praised at the meeting?（七）只能使用w h i c h的情况●1.关系代词前有介词时；●2.先行词本身是t h a t时；●3.非限定定语从句●口诀:要有w h i c h别着急，●介词提前逗隔离。
●e.g:1.T h i s i s t h e c l a s s r o o m i n w h i c h w e s t u d i e d f o r t w o y e a r.●2.S h e h a s t w o d o l l s，w h i c h a r e f r o m h e r p a r e n t s补充：关系副词的用法（1）when指时间，其先行词表示时间，在句中作时间状语。
例如：This was the time when he arrived.这是他到达的时间。
（2）where指地点，其先行词表示地点，在句中作地点状语。
例如：This is the place where he works.这是他工作的地点。
（3）why 指原因，其先行词是原因，起原因状语作用。
例如：Nobody knows the reason why he is often late for school.没人知道他为什么上学总迟到。
注意下面句子：This is the place where Li Bai once lived.这是李白曾经生活过的地方。
（where先行词是place）上面这个句子不可以将where改为that，因为that不能作为表示地点的关系副词。
试比较下句：This is the place that Li Bai once visited.这是李白曾经游览过的地方。
（that的先行词同样是place，但这个that是关系代词，在定语从句中作宾语，可以省略，还可以用which替换）单项选择：● 1. This is the bag _____ my mother bought yesterday.● A. that B. who C. whom D. this● 2. The girl _____ you saw in the street is Mary.● A. that B. whose C. which D. as● 3. Is this the factory _____ a lot of students visited yesterday?● A. the one B. which C. who D. whom●※4.Is this factory a lot of students visited ?A. the oneB. whichC. whoD. who● 5. The only language _____ is easy to learn is the mother tongue.● A. which B. that C. / D. it● 6. The girl handed everything _____ she had picked up in the street to the police.● A. which B. in which C. that D. all●※7. _____ cleans the blackboard should be praised.● A. That B. Who C. The one who D. The students who●注意：●①当关系词作定语从句的主语时，从句谓语动词的形式应与先行词的人称和数保持一致。
②若句中无先行词，先补出先行词再判断用法。
（4,7题）观察下列句子：1.这就是救了那个孩子命的医生.This is the doctor who saved the boy’ s life2.正在跑步的那个人是我的叔叔.The man who is running is my uncle.3.住在隔壁的那个小伙的是教师.The young man who lives next door is a teacher.注意：定语从句的时态不受主句影响。
用关系代词或关系副词将下列每对句子连成一个复合句1. The boy is my younger brother. He was here a minute ago.2. The old man is a professor. He teaches chemistry in a college.3. Beijing Hotel is near Tian An Men Square. The foreign visitors live there.4. The woman is here now. You were talking about her.5. I enjoyed reading the book. You gave me a book last week.用适当的关系代词that，which，who，whom填空。
