定语从句，图表口诀耍起来!

　　对于英语学习者来说，单词毫无疑问是基础，而语法则是架构，单词需要依照语法规则组成句子。英语考试中有一个大家都非常熟悉的常客——定语从句，无论是在单项选择、完型填空，还是在阅读理解和书面表达中也是变换着各种形式进行考察。因此，大家要学会在听课和刷题中不断揣摩其中存在的规律，再反过来题目精炼。

　　一、定语从句起了形容词的作用，在句子中修饰一个名词或代词。

　　被修饰的词叫做先行词，引导定语从句的词叫关系词，他的作用一是放在先行词与定语从句中间起了连接作用，二是在从句中担当一个成分，并与先行词要保持数的一致。

关系词		先行词	从句成分	例 句	备 注
关关系代 词	who	人	主语	Do you know the man who istalkingwith your mother?	whom, which和that在从句中做宾语时，常可以省略，但介词提前时后面关系代词不能省略，也不可以用that
	whom	人	宾语	Mr. Smith is the person with whom I am working The boy (whom) she loved died in the war..
	whose	人或物	定语	I like those books whose ics areabout history. The boy whose father works abroad is my deskmate.
	that	人或物	主语，宾语	A plane is a machine that can fly. She is the pop star (that) I want to see very much.
	which	物	主语，宾语	The book (which) I gave you was worth $10. The picture which was about the accident was terrible.
	as	人或物	主语，宾语	He is such a person as is respected by all of us. This is the same pen as I lost yesterday.	as做宾语一般不省略
关关系副 词	when	时间	时间状语	I will never forget the day when we met there.	可用on which
	where	地点	地点状语	This is the house where I was born.	可用in which
	why	原因	原因状语	I can’t imagine the reason why he turned down my offer.	可用for which

　　二、that与which, who, whom的用法区别

情 况	用法说明	例 句
只用that的情况	1.先行词为all, everything, anything, nothing, little, much,等不定代词时 2.先行词被all, any, every, each, much, little, no, some, few等修饰时 3.先行词有形容词较和序数词修饰时 4.先行词既指人又指物时 5.先行词被the only, the very修饰时 6.句中已经有who或which时，为了避免重复时	1.He told me everything that he knows. 2.All the books that you offered has been given out. 3.This is the best film that I have ever read. 4.We talked about the persons and things that we remembered. 5.He is the only man that I want to see. 6.Who is the man that is making a speech?
只用which, who, whom的情况	1.在非限制性定语从句中，只能用which指代物，用who/whom指人 2.在由“介词+关系代词”引导的定语从句中，只能用which指物，whom指人。 3.先行词本身是that时，关系词用which, 先行词为those, one, he时多用who。	1.He has a son, who has gone abroad for further study. 2.I like the person to whom the teacher is talking. 3.Those who respect others are usually respected by others.

　　三、as、which和that的区别

从句	区 别	例 句
限制性定语从句中	名词前有such和the same修饰时，关系代词用as,不能用which	He is not such a fool as he looks. Don’t read such books as you can’t understand.
非限制性定语从句中	as和which都可以指代前面整个主句。如果有“正如，象”的含义，并可以放在主句前，也可以放在后面，那么用as；而which引导的从句只能放主句后，并无“正如”的意思。	They won the game, as we had expected. They won the game, which we hadn’t expected. As is well known, he is a famous film star in the 1980s.
the same... as和 the same ...that	the same... as指同类事物 the same ...that 指原物	That’s the same tool as I used last week.（同类工具，不是同一把） That’s the same tool that I used last week.那就是我上周用过的工具。

　　注意：the way 做先行词时，定语从句可由that, in which 引导或不用引导词。