初三英语知识点二.docxVIP

一、定语从句：在复合句中 ， 修饰名词或代词的从句叫定语从句 ， 被修饰的名词或代词叫先行词 ， 引导定语从句的有关系代词 who, whom, whose, which, that等和关系副词where, when, why等 ， 关系代词和关系副词在定语从句中担任句子成份。 1.由who引导的定语从句中 ， who用作主语 ， 如 ： This is the boy who often helps me. 2.由whom引导的定语从句中，whom用作宾语，如：The man whom you are waiting for has gone home. 3.由whose引导的定语从句中 ， whose用作定语 ， 如 ： Do you know the girl whose skirt is white? 4.由which引导的定语从句中，which用作主语或谓语动词的宾语或介词的宾语，如： The room in which there is a machine is a work shop. The river which is in front of my house is very clean. This is the pen which you want. 注意 ： (1)whom, which用作介词宾语时 ， 介词可放在 whom、which之前 ， 也可放在从句原来的位置上；但在含有介词的动词固定词组中，介词只能放在原来的位置上。如： He is the very person whom we must take good care of. (2)引导非限制性定语从句时，必须用关系代词which，不用that,如：I have lost my bag, which I like very much. (3)关系代词在句中作主语时，从句的谓语动词的人称和数必须和先行词保持一致。 5.由that引导的定语从句中，that可以指人或物，在从句中作主语或谓语动词的宾语，但不能放在介词后面作介词宾语，如： The book that I bought yesterday was written by Lu Xun.注意在下面几种情况下必须用 that引导定语从句。 (1)先行词是不定代词all, few, little, much, something, nothing, anything等 ， 如 ： All that we have to do is to practise English. (2)先行词被序数词或形容词最高级所修饰，如 The first letter that I got from him will be kept. (3)先行词被all, any, every, each, few, little, no, some等修饰 ， 如 Ive eaten up all the food that you gave me. (4)先行词被the only, the very, the same, the last修饰时如 He is the only person that I want to talk with. (5)先行词既有人又有物时，如: They talked about persons and things that they met. (6)当句中已有who时 ， 为避免重复 ， 如 ： Who is the man that is giving us the class? 6.由when, where, why引导的定语从句，如: I dont know the reason why he was late. This is the place where we have lived for 5 years. Ill never forget the day when I met Mr Li for the first time. 注意：先行词是表示地点时，如果从句的谓语动词是及物的，就用 that(which)，如果从句的谓语动词是不及物的，就用where引导。This is the house Which /that he has lived in for 15 years.(Where he has lived for 15 year.) 7. 限制性定语从句和非限制性定语从句 (1)限制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。引导非限制性定语从句的关系代词有who, whom, whose, which, of which等，这些关系代词都不能省略。 (2)非限制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