定语从句（一）定语从句一般由关系代词和关系副词引导1、关系代词：who, whom, whose, which, that, as2、关系副词：when, where, why关系代词和关系副词必须位于从句之首，主句先行词之后，起着连接先行词和从句的作用， 同时在从句中又充当句子成分。e.g. She is the girl who sings best of all.（关系代词who在从句中作主语）The comrade with whom I came knows French.（whom在从句中作介词with的宾语）3、关系代词和关系副词的用法：1）当先行词为人时用who 作主语，whom作宾语；2）当先行词为物或整个句子时用which ，可作主语或宾语；3）先行词为人、物时用that ，可作主语或宾语；4）whose用作定语，可指人或物；5）关系副词when（指时间，在定语从句中作时间状语，where（指地点，在定语从句中作地点状语），why（指原因，在定语从句中作原因状语）。（二）限制性定语从句与非限制性定语从句1、限制性定语从句：从句与主句关系密切，去掉从句，主句意义不完整，甚至不合逻辑。e.g. I was the only person in our office who was invited.（去掉定语从句，意思就不完整）2、非限制性定语从句：从句对先行词关系不密切，去掉定从句，意思仍然完整。形式上用逗号隔开，不能that用引导。e.g. Tom’s father, who is over sixty, still works hard day and night.（who引导非限制性定语从句，整个句子可分成两句来翻译）（三）使用定语从句时特别注意的几个问题1、that与which的区别。1）用that而不用 which的情况：①先行词为不定代词all, anything, nothing, …；②先行词有最高级修饰，有序数词修饰；③先行词有only, very, any等词修饰；④先行词既有人又有物时。e.g. There is nothing that can prevent him from doing it. 没有什么能阻止他不干那件事。The first place that they visited in Guilin was Elephant Trunk Hill. 在桂林他们所参观的第一个地方是象鼻山。This is the best film that I have ever seen. 这部电影是我看过的最好的一部。Mr Smith is the only foreigner that he knows. 史密斯先生是他认识的唯一的外国人。2）用which而不用 that的情况：①引导非限制性定语从句；②代表整个主句的意思；③介词 + 关系代词。e.g. He had failed in the maths exam, which made his father very angry....
