The document defines several parts of speech: nouns can be concrete, abstract, or proper and denote people, places or things. Pronouns replace nouns in sentences and can be subject or object pronouns. Articles precede nouns and can be a, an, or the. Adjectives describe nouns and pronouns. Verbs denote actions or states of being. Adverbs modify verbs, adjectives, and other adverbs. Conjunctions join clauses or sentences. Prepositions give direction to nouns.