初中英语知识点总结:定语从句
得学定语从句，得了解什么是定语。定语是用于限制、装饰专有名词或介词的。例如，a good book, good便是定语。那麼复合句中装饰专有名词或介词的状语从句就叫做定语从句。定语从句由关系代词或关系副词正确引导，等同于修饰词，在句中作定语。被定语从句装饰的词叫先行词，定语从句一般放到先行词的后边。正确引导定语从句的关联词语称之为关系词，关系词有关系代词和关系副词。关系代词有that, which, who, whom, whose等，肯定并没有what;关系副词有where, when, why,how等。关系词放到先行词和定语从句中间，起衔接功效，与此同时又作定语从句的某一成份。
一、关系代词引导的定语从句
1、由who, whom, that，whose正确引导的状语从句
这种词替代的先行词是人的专有名词或介词，who作谓语指人，whom作宾语指人，that既能作谓语又能作宾语(作宾语可以省去)，可以指人还可以指物。whose 用于指人或物，只作为定语。
(1) is he the man who/that wants to see you? 他是那一个见到你的男人吗?(who/that在状语从句中作谓语)
(2) he is the man whom/ that i saw yesterday. 他便是我昨日见的那人。(whom/that在状语从句中作宾语)
(3) the man whom you spoke to just now is our english teacher 你刚讲话的那个人是我们的英语教师
(4) he man whose son is a doctor is our professor. 那一个孩子是医师的男人是大家的专家教授。
2、由which, that正确引导的状语从句
他们所替代的先行词是事情的专有名词或介词，在状语从句中能作谓语、宾语等，作宾语时可以省去，例如：
(1) prosperity which / that had never been seen before appears in the countryside. 乡村发生了空前绝后的兴盛。(which / that在状语从句中作谓语)
(2) the package (which / that) you are carrying is about to come unwrapped. 你拿那一个包囊即将散掉了。(which / that在状语从句中作宾语)
留意： 意味着物时常用which，但在以下状况选用that而不用which：
a)先行词是anything, everything, nothing , none等不定代词时;
b)先行词由every, any, all, some, no, little, few, much等装饰时，这时的that常被省去;
c)先行词前有序数词或被形容词最高级装饰时;
d)先行词中不仅有人又有物时;
e)全部句中前边已经有which，who,that时;
f)当先行词为物并且做好表语时;
g)先行词为one时;
h)先行词与此同时又被the only,the very,the same装饰时;
二、关系副词正确引导的定语从句
1、when指时长在定语从句中做时间状语也可做连接词用
i still remember the day when i first came to the school.
2、where指地址在定语从句中做地点状语 shanghai is the city where i was born.
3、why指缘故在定语从句中做原因状语 ，用在reason 后边。 please tell me the reason why you missed the plane.
普遍考法
针对定语从句的考察，多以单项选择题的方式考察学员熟练掌握的工作能力。一般情形下，常从关系词的实际意义和功用的视角考察，关键是that,which,who正确引导的定语从句。
典型性练习题：
you're the only person ______i've ever met ______could do it.
a. who b. whom c. whom d. who
分析：先行词person后有两个定语从句,第一个状语从句省去了关系代词whom.由于, whom作状语从句中met的宾语,可以省去.第二个状语从句who could do it.who在从句中作谓语,不能省去.
回答：d
错误观念提示
当表示时间或位置的专有名词作先行词时，要辨别出他们在状语从句中作状语或是谓语或宾语。作状语时要关系副词，相反用关系代词。
典型性练习题：
i can never forget the day _______ we worked together and the day ______ we spent together.
a. when; which b. which; when c. what; that d. on which; when
分析：2个先行词the day全是表示时间的专有名词,但第一个空白要填的关系词在状语从句中作状语,因而要用关系副词when. 第二个空白要填的关系词在状语从句中作形容词spent的宾语,因而要用关系代词which或that来正确引导定语从句.
回答：a
