定语从句后面的动词怎么是ed形式

定语从句中的动词的时态要根据具体情况选择，不一定都是-ed形式。

如 I like the girl who walks to school everyday.I like the girl who danced yesterday.I like the girl who has finished her college study.定语从句的用法定语从句由关系代词who、whom、whose、which、what、as和关系副词where、when、why等引导，但须记住：

1. what不能引导定语从句.2.关系词的分析须考虑它在定语从句中的成分。一.指人的关系代词有who、whose、whom、that. 试分析：The old man who/whom /that we visited yesterday is a famous artist.Miss Wang is taking care of the child whose parents have gone to Beijing .The man with whom my father shook hands just now is our headmaster. （=The man who/whom that my father shook hands with just now is our headmaster.）注：A． 指人时有时只用who不宜用that。

1．先行词为one、ones或anyone（1）The comrade I want to learn from is the one who studies hard and works hard.（2）Anyone who breaks the law should be punished.2．先行词为these时These who are going to Beijing are the best students of our school.3．在there be 开头的句子中There is a student who wants to see you.4．一个句子中带有两个定语从句，其中一个定语从句的关系代词是that，另一个宜用who，以免重复。The student that won the first prize is the monitor who works hards.5．在非限制性定语从句中A。I met a friend of mine in the street, who had just come from Japan.B．主句以who开头的句子中,只用that,不用who。that和which引导定语从句的区别that which在代物时常常可以通用,但有时只宜于用which ,不用that(1) 关系代词前有介词时.Thisis the hotel in which you will stay.(2)如有两个定语从句,其中一句的关系代词是that,另一句宜于用which.Let me show you the novel that Iborrowed from the liberary which was newly open (新开放) to us.注意2thatwhich在代物时常常可以通用,但有时只宜于用that ,不用which.(1) 先行词是形容词最高级或者它的前面有形容词最高级时This is the best that has been used against air pollution(反对空气污染) incities.English is the most difficult subject that you will learn duringthese years.(2) 先行词是序数词,或它的前面有一个序数词时He is the last person thatI want to see.(3) 主句中已有疑问词时Which is the bike that you lost (4) 先行词既有人又有物时The bike and its rider that had run over (撞倒了)anold man were taken to the police station.(5)先行词是all,much,little,something,everything,anything,nothing,none,the one等代词时You should hand in all that you have.We haven’t got much thatwe can offer you.I mean the one that you talked about just now.(6) 先行词前面有only,any,few,little,no,all,one of,the same,the very等词修饰时The only thing that we can do is to give you some money.Li Mingis the only one that got full marks (满分)in our class.Li Ming is one ofthe students that want to be teachers in our class.(7)有两个定语从句,其中一个关系代词已用which,另外一个宜用thatEdison built up a factory(办了一个工厂)which produced things that had never been seen before.定语从句的关系副词Where的用法:若先行词指地点且其在定语从句中充当地点状语.This is the house+I was born in thehouse. (=I was born there)介词短语 副词=This is the house where Iwas born.这就是我在那儿出生的房子.先行词 关系副词in which I was born.介词+关系代词which I was born in.关系代词这里作介宾的which和that可以省略