A grammar guide is a resource that provides rules and explanations about the structure of a language. It helps users understand how to use words, phrases, and sentences correctly. These guides often cover topics like punctuation, verb tenses, and sentence structure, making them useful for students, writers, and anyone looking to improve their language skills. Many grammar guides are available in various formats, including books, websites, and apps. They can range from simple overviews for beginners to detailed references for advanced users. Some popular examples include The Elements of Style and online platforms like Grammarly and Purdue OWL.