This document discusses adjective clauses, also known as relative clauses. It defines adjective clauses as dependent clauses that modify nouns called antecedents. Adjective clauses function like adjectives by providing extra information about nouns. The document covers the placement of adjective clauses, the different types of relative pronouns used to introduce clauses, and the two types of clauses - subject clauses and object clauses. It also discusses modifying place and time within adjective clauses.