The document defines clauses and phrases. It states that a clause contains a subject and verb and can be independent or dependent. An independent clause makes sense as a sentence on its own, while a dependent clause does not. There are three types of dependent clauses: adjective clauses that modify nouns, adverb clauses that modify verbs and adjectives, and noun clauses that function as nouns. The document also defines phrases as groups of words without a subject-verb structure, including noun, verb, adjective, adverb, and preposition phrases.