一．定语从句：用复合句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和关系副词.1）robert johnson was a blues singer and a guitarist（ who has been called the father of rock and roll）. ↓ ↓ 先行词 关系代词2）the room（ where the boys were fed ） was a large stone hall. ↓ ↓先行词 关系副词定语从句分为限制性定语从句和非限制性定语从句限制性定语从句常放于被修饰词之后，与其之间没有逗号隔开，如：this is the room where he lived last year.非限制性定语从句与他所修饰的名词或代词之间常有都好隔开，如：he passed all the exams, which made his mother very happy.非限制性定语从句不能由 that 来引导三．常见的关系代词和关系副词
