> 定语：修饰限定名词或代词的成分 > 定语从句：用一个句子表达定语的含义，在剧中做定语，修饰一个名词或代词。被修饰的名词叫做<先行词>。其后的从句就是定语从句。由关系词（关系代词或关系副词）引出。 # 关系代词 当使用一个句子充当定语来修饰限定名词或代词时，需要使用一个代词联系起来从句和主句，这个代词就叫做关系代词 关系代词在从句中做一定的成分，代替先行词，起到链接先行词和从句的作用。 常用的关系代词： * that (代替人/事物) * who(代替人) * which(代替事物) * whom(代替宾格的人) * whose(代替某人的/某事物的) ``` The girl whom/that I spoke to is my cousin. 我和她说话的那个女孩是我的表姐。 * 先行词：The girl * I soke to is my cousin这个从句就是用来修饰限定前面的The girl * 从句中 I是主语，spoke to是谓语，但是缺少宾语，那么关系代词whom/that就代替的是句中的宾语，被提到从句最前面用以连接先行词和后面的从句。 ``` * which,that在从句中作宾语是可以省略 ``` He came back for the book which/that he had forgotten. He came back for the book which/that was on the desk. ``` # 关系副词 * when * where * why ## why 修饰表示原因的名词 eg: the reason ``` We don't know the reason why he didn't show up. ``` ## when 修饰表示时间的名词 eg: next week ``` We'll put off the picnic until next week,when the weather may be better. ``` ## where 修饰表示地点的名词 eg: the place ``` We don't know the place where he lives. ```