定语从句有两个重要概念:先行词和关系词。定语从句的核心内容就是围绕先行词和关系词展开的。被定语从句所修饰的对象称为先行词。重复指代先行词,起连接主句和从句的作用,并且在定语从句中充当一定成分的连接词称为关系词。关系词又可以分为两大类:关系代词和关系副词。关系代词主要包括who,whom,which,that和whose,这些词主要起着代词的作用,在定语从句里充当主语或宾语(但whose作定语);关系副词则包括when,where和why,这些 Attributive clause has two important concepts: antecedent and relational words. Attributive clause core content is around the antecedent and related words to start. Objects modified by the attributive clause are called antecedents. Repeated refers to the antecedent, from the main clause and clause to connect the role, and attributive clause as a part of the connective is called the relationship between words. Relationship words can be divided into two categories: relational pronouns and relational adverbs. The relational pronouns mainly include who, whom, that, and whose key pronouns play the role of subject or object (but attributives), and relation adverbs include when, where and why