This document provides rules for forming possessives and plurals in English nouns. It explains that to make a singular noun possessive, add an apostrophe s, and to make a plural noun that ends in s possessive, add an apostrophe after the s. The document also outlines rules for making nouns plural based on their ending letters, such as adding es to nouns ending in s, x, sh, or ch, and changing y to i and adding es for nouns ending in a consonant and y.