This document provides definitions for different parts of speech in English including nouns, verbs, pronouns, adverbs, conjunctions, interjections, and prefixes. Nouns name people, places, things, and ideas. Verbs indicate actions. Pronouns replace nouns. Adverbs modify verbs, adjectives, other adverbs, phrases, or clauses indicating manner, time, place, cause, or degree. Conjunctions link words and phrases. Interjections convey emotion. Prefixes added to the beginning of words change their meaning.