This document provides an overview of comma rules and common errors involving commas. It covers basic comma rules such as using commas to set off introductory material, between two independent clauses joined by a conjunction, around interrupting words or phrases, in quotations, to separate items in a series, and in dates and addresses. It also discusses comma splices and run-on sentences as common errors and gives solutions to fix them, such as using periods, conjunctions, subordinating conjunctions, or semicolons. Exercises are included to help reinforce the concepts.