This document provides examples of 15 commonly misused words and how to correctly use them. It explains the differences between your and you're, affect and effect, there, their and they're, to, too and two, lie and lay, who and that, and which. For each set of words, it gives examples of correct usage. The document concludes by stating there are other commonly misused words that will be discussed later, and provides a link to learn more about marketing books.