This document discusses the classification of clauses. It defines clauses as groups of words that contain a subject and predicate, and may or may not be independently meaningful. Clauses are classified as either independent/principal clauses or dependent/subordinate clauses. Independent clauses can stand alone as sentences, while dependent clauses need to be attached to an independent clause to be complete. Dependent clauses can function as nouns, adjectives, or adverbs. Noun clauses function like nouns, adjective clauses qualify nouns, and adverb clauses modify verbs, adjectives or other adverbs. The document provides examples to illustrate each type of clause.