The document provides instruction on the use of apostrophes in the English language. It defines apostrophes and explains that they are used to show possession or omitted letters. The document outlines two simple rules for using apostrophes: to show contractions and to indicate possession. It provides examples of how to use apostrophes with pronouns, nouns to show ownership, and for omission. The document also clarifies when not to use apostrophes, such as with plural nouns not showing possession.