关系代词在定语从句中的用法 一、判断定语从句引导词的一般规律：1）who，whom，that用来指人，who，that在从句中作主语或宾语，作主语时不能省，做宾语时可以省，whom只能做宾语，也可以省 eg: I love singers who/that write their own lyrics.（作主语）The man （who/whom/that） you want to meet has come.你要见的人来了作宾语）The man who /that gave us a talk on science yesterday is a famous scientist. （作主语）She is the old woman（ whom/that/who ）I saw this morning. （作宾语） 2）whose既可用来指代人也可用来指代事物，一般置于名词前,在从句中充当定语 eg:This is the girl whose math book is lost. 这就是丢了数学书的女孩。
指人，作定语） The house whose windows are closed is mine. 窗户都关着的这栋房子就是我家指物，作定语）3）which，that用来指代事物，在从句中作主语或宾语 eg: They planted the trees which/that didn’t need much water.（指物，作主语）The fish (which/that) we bought were not fresh.（指物，作宾语） The train which/that has just left is for Shanghai. （指物，作主语） The noodles （which/that ）I cooked were delicious .（指物，作宾语）二、注意在下面几种情况下必须用that而不用which引导定语从句：①先行词是不定代词all,few,little,much,something,nothing,anything等eg：All that we have to do is to practise every day.He won’t tell you anything that he has heard about it. ②先行词被all,any,every,each,few,little,no,some等修饰。
eg：I have read all the books(that)you gave me. You can take any toy that you like. 你可以拿走你喜欢的任何玩具③先行词被序数词或形容词最高级所修饰eg：The first lesson that I learned will never be forgotten.This is the best film I’ve ever seen.④先行词被the only,the very,the same,the last修饰时，eg： The only language that is easy to learn is the mother tongue. ⑤先行词既有人又有物时，eg：They talked of things and persons that they remembered.⑥. 由who或which提问的句子；eg:Which is the house that caught fire yesterday? 昨天失火的是那座房子？Who is the man that is reading the book over there?（作主语）三、通常使用which, 不用that的场合：1.介词提到关系代词前时，如 for which , on which, in which, of which 等；eg:Dong guan is the place in which I was born. 2.先行词是that时。
eg: What is that which you are holding in your hands?四、用whom而不用who的情况:介词提到关系代词前时eg: She is the girl with whom I went there.The person to whom you just talked is Mr. Li.This is the boy behind whom I sit.五、who，that在很多情况下可以通用，但是有些情况只能用who:1. 先行词是one, ones, anyone的时候宜用who.Don’t tell anyone about the news who oughtn’t to know it.2. 先行词为those的时候，宜用who为关系代词Those who made no mistakes in today’s exercises please raise your hands.3. 在there be 开头的句子中:There is an old man who wants to see you.六、限制性定语从句与非限制定语从句:①限定性定语从句是句中不可缺少的组成部分，主句和从句之间不用逗号分开，引导非限定性定语从句的关系代词有who,whom,whose,which，这些关系代词都不能省略；②非限定性定语从句是对主句先行词的补充说明，没有这种从句不影响主句意思的完整，一般用逗号把主句和从句分开。
关系代词用which，不用that；指人时可用who，eg： I have two sisters,who are both students.Football, which is a very interesting game, is played all over the world.My father , who is a teacher , is very kind to the students.。