2、sapoliceman.该句中，whoisshakinghandswithmyfather是定语从句，修饰先行词theman，“who”是引导定语从句的关系词，在定语从句中代替先行词theman，在定语从句中作主语。注意：弄清楚关系词在定语从句中充当什么成分，是掌握定语从句、选择好关系词的关键。二关系代词引导的定语从句引导定语从句的关系代词主要有who,whom,whose,which,that等。它们分别代替前面的先行词，并在定语从句中作主语、宾语或定语。1.who 指人，在定语从句中作主语。The boys who are playing football are
3、from Class One. 正在踢足球的男孩是一班的。Yesterday I helped an old man who had lost his way. 昨天我帮助了一位迷路的老人。That is the teacher who teaches us physics. 那就是教我们物理的老师。2.whom 指人，在定语从句中做宾语，常可省略，在口语或非正式文体中常可用who 来代替。Li Ming is just the boy(whom)I want to see. 李明正是我想要见的男孩。The professor(w
4、hom)you are waiting for has come. 你正在等的教授已经来了。The girl(whom)the teacher often praises is our monitor. 老师经常表扬的那个女孩是我们的班长。3.which 指物，在定语从句中做主语或宾语，做宾语时常可省略。Football is a game which is liked by most boys. 足球是大多数男孩所喜欢的运动。He likes to read books which are written by foreign writers.
5、他喜欢外国作家写的书。The film (which) they went to see last night was not interesting at all. 他们昨晚看的电影一点意思也没有。4.that 指人时，相当于who 或whom；指物时，相当于which.。在定语从句中作主语或宾语，作宾语时常可省略。Heisthemanthat/wholivesnextdoor.他就是住在隔壁的那个人。Where is the man(that/whom)I saw this morning? 我今天早上看到的那个人在哪儿？Thedress(that/which
6、)Annboughtdoesn’tfitherverywell.安买的衣服不太合身。5.whose 指人、物皆可，与后面的名词有所属关系，在定语从句中做定语。I visited a scientist whose name is known all over the country. 我拜访了一个全国知名的科学家。He has a friend whose father is a doctor. 他有一个爸爸当医生的朋友。I once lived in the house whose roof has fallen in. 我曾经住在那幢屋顶已经倒塌了的房子里。
7、注意：指物时，常用以下结构来代替：Thehousewhosewindowsarebrokenisempty.Thehousethewindowsofwhicharebrokenisempty.Do you like the book whose cover is yellow?Do you like the book the cover of which is yellow? 三“介词+关系代词”引导的定语从句关系代词在从句中作介词宾语时，可以跟介词一起放在从句与主句之间（that,who不可以），也可以把介词放在从句中有关
