英语定语从句（形容词性从句）用法一、定义：定语从句在复合句中做定语，修饰一个名词或代词，被修饰的名词，词组或代词即先行词。
定语从句通常出现在先行词之后，由关系词（关系代词或关系副词)引出. 关系代词和关系副词必须位于从句之首，主句先行词之后,起着连接先行词和从句的作用，同时在从句中又充当句子成分。
关系代词有： who， whom, whose， that, WhiCh 等。
关系畐U词有: Whe n， where, Why等。
先行词+ 关系词+ 定语从句Mary is a girl WhO has IOng hair先行词关系词定语从句关系代词关系副词（which， who, whom， whose， tha t （where， When , Why二、关系代词和关系副词的用法：1）当先行词为人时用who作主语，whom 作宾语（可省)；2）当先行词为物或整个句子时用 WhiCh ，可作主语或宾语；3）先行词为人、物时用that ,可作主语或宾语（可省);4） whose用作定语，可指人或物;5）关系副词When (指时间，在定语从句中作时间状语，Where （指地点，在定语从句中作地点状语)，why （指原因，在定语从句中作原因状语）。
关系词在定语从句中作主语时，从句的谓语动词必须和先行词在人称和数量上保持一致.小结：who, whom, WhOSe（Of which), that （指人 /物）, WhiCh （指物）(主语）（宾语）（定语）Where= in WhiCh （指地点，在定语从句中作地点状语）When= On WhiCh （指时间，在定语从句中作时间状语Why （指原因，在定语从句中作原因状语）三、关系词的选择1. 首先判断先行词。
2. 先行词确定后，再看关系词在从句中作什么成分，然后正确选择关系词.4. 定语从句要避免成分重复5. 定语从句要避免漏用先行词6. 含有介词的短语动词一般不拆开TheSe are the tree which were PIa nted IaSt yearShe is the girl who SingS best of allThe StUdent who anSWered the question is my CIaSSmateThe doctor whomyou ’ r talking about has gone homeI know the lady WhOSehUSband works in a hospitalWhereiS my coat WhiCh I bought this morning？I have n ever forgotte n the day When I met youThe is the room Where he livesThe is no reasOn Why you should leaveThe woma n (whom/ that）they Wan ted to ViSit is a teacher。
The man( whom/who） I talked to is Mr。
Li.四、定语从句中的that， who用来指人时的用法在下列情况下多用或须用who①关系代词在从句中作主语时，多用who.Do you know the man who spoke just now？The doctor who treated me WaS Very experie need。
②先行词为 all, anyone， one， ones等时,多用 who。
All who heard the n ews Were excited.AnyOne who breaks the rule will be PUni shed.③先行词为those和people时多用who.Those who Want to go PIeaSe Sig n their n ames here。
People who Can See SOmetimeS act just as foolishly。
④在非限制性定语从句中作主语须用who，作宾语须用whom.TOm S father, who is Ver sixty， still works hard.Mr 。
Green， whom you SaW in the Iibrary yesterday, will teach US PhySiCS n ext term.⑤在被分割的定语从句中须用who。
A new teacher will Come tomorrow who will teach you Germa n。
⑥在以there be开头的句子中多用 who。
There is a Stra nger who WantS to See Our headmaster。
⑦一个句子中带有两个定语从句, 其中一个关系代词是that,另一个须用who。
The StUdent who WaS PraiSed at the meeting is the monitor that is modest and StUdieS Very hard.五、只用that不用WhiCh的情况1、当先行词是 all, little, few, much， SOmething, everything， anything，nothing, none 等不定代词时。
如： EVerythi ng that happe ned the n WaS like a n ightmar当时发生的一切就像是一场噩梦.I will tell him all that you told me at the ball。
我要把你在舞会上跟我说的话全都告诉他。
2、当先行词被only， any， few， little， no, all， just， Very （恰好的，表示强调)等词修饰时。
例如：The only thi ng that We could do WaS to Wait我们能做的只是等待。
That ’ the Very thing that We Can do那正是我们能做的事。
3、当先行词是序数词、形容词最高级或先行词被序数词或形容词最高级修饰时. 例如：The first place that We ViSited WaS the Great Wall我们参观的第一个地方是长城。
ThiS is the best no Vel that I have ever rea这是我看过的最好的小说。
4、被修饰词为数词时。
例如：YeSterday I CaUght two fish and PUt them in a basin of water。
Now you Can See thetwo that are still alive。
昨天我捉到了两条鱼，把它们放在一盆水里。
你可以看到那两条鱼还活着呢5、主句是There be结构，修饰其主语的定语从句宜用that作关系代词修饰物。
例句:There ' still a room that is free。
还有一个空房间.6、先行词中同时包括人和物时。
例如：We talked about the people and the villages that We remembere d 们谈论了我们记得的人和村子。
He asked about the factories and WorkerS that he had ViSite他问起他去过的这几家工厂和工人的情况。
7、当主句中有who， WhiCh时，而定语从句中也要用到 who或WhiCh时，为了避免who∙∙who， WhiCh…WhiCh等重叠,定语从句要用that引导.例如：WhoiS the man that is Sta ndi ng by the door？占在门边的那个男人是谁？WhiCh of the two cows that you keep PrOdUCeS more milk?你养的那两头奶牛中哪一个产奶多？8人或物在定语从句中表语时,用that引导定语从句，而that通常也可以省略。
例如：He is no Ion ger the man that he Wa他不再是过去的他.六、关系副词When指时间，关系副词Where指地点,在定语从句中作状语.即使先行词是时间地点,若作从句中的宾语，只能用关系代词that, which。
巩固练习Fill in the gaps：1. We talked about the people and the villages __ We remembered。
2. The Wi nd blew dow n the tallest tree __ i s in front of our school gate。
3. ThiS is the Very thi ng _I WaS Iook ing for。
4. ThiS is the SeC Ond no Vel __ I have ever read.5. There is nothing in the world ____ Can frighte n me。
6. Who is the man _______ is read ing Un der the tree?7. He is no Ionger the man _____ he was。
单选题1. --------------------------------------- I still remember the day I joined the armyA. WhiCh B。
Whe n C. On that D. i n WhiCh2. ThiS is the factory - We ViSited last yearA. Where B。
WhiCh C. Why D. who3. HaVe you found the woman—-PUrSe WaS lostA。
that B. who C。
whose D. whom4. Where is the Wi ndow -- glass WaS broke n?A. WhiChB. that C。
whose D. its5. ThiS is the book-- I WantA。
that B。
What C。
in WhiCh D. as6. She is a new teacher ---- will teach you En glishA. who B。