This document provides rules for making nouns plural or possessive in English. It explains that nouns ending in f or fe change the f to v and add es, while others add just s. Nouns ending in a vowel and o add s, as do most singular nouns. To make a singular noun possessive, add an apostrophe s, and to make a plural noun possessive ending in s, add an apostrophe after the s. Special plural forms are given for some nouns.