The document discusses adjective clauses. It defines an adjective clause as a dependent clause that modifies or provides more information about a noun. It explains the different types of relative pronouns (who, whom, which, whose, that) and how they are used based on whether the noun is the subject or object of the clause. Examples are provided to illustrate how different nouns can be modified with adjective clauses using the appropriate relative pronouns. Exercises are included for students to practice forming adjective clauses.