The term "grammar errors" refers to mistakes made in using proper grammar and punctuation while writing or speaking. Grammar is a set of rules that dictate how words are arranged, used together, and formatted within sentences and paragraphs. When these rules are not followed correctly, it can lead to confusion for the reader or listener, and may even change the intended meaning of what was said or written. Some common grammar errors include subject-verb agreement issues, incorrect use of pronouns, improper sentence structure, and missing or misplaced punctuation marks. Proper attention to detail in terms of grammar can greatly improve clarity, readability, and overall communication effectiveness.