This document discusses the different parts of speech in English language. It explains that words can be categorized into different types or classes based on their functions, similar to how parts of a house have different jobs. The 8 basic parts of speech are nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections. It provides examples and explanations of how words are formed by adding prefixes and suffixes, and by joining two words together in different ways such as noun+noun or verb+noun.