This document discusses common grammar errors in formal writing. It begins by defining formal and informal writing, noting that formal writing is used in academic, professional, and legal contexts. It then lists 12 common grammar errors seen in formal writing, including issues with verb tense, subject-verb agreement, run-on sentences, comma splices, ambiguous modifiers, redundant words, contractions, capitalization, spelling, and colloquial language. For each error, it provides an example of correct and incorrect usage. The document emphasizes that grammar errors are a natural part of the writing process and advocates learning from mistakes.