This document provides definitions and explanations of key concepts in grammar: - Grammar is the way we organize language sounds and signs into something meaningful, and the study of how language is used in an organized way. - Morphology is the grammar of words and their forms, and deals with word classes and affixes that change word meanings or classes. - Syntax is the grammar of word order and sentence structure, and how rearranging words creates different meanings. - Discourse analysis examines the grammar of longer texts through techniques used to achieve different effects across conversations, letters, and other written works.