This document outlines 5 rules for forming the comparative form of adjectives in English. Rule 1 states that most adjectives form the comparative by adding -er, such as taller, shorter, stronger. Rule 2 specifies that adjectives ending in a single consonant preceded by a single vowel double the consonant and add -er, like bigger, fatter. Rule 3 says some adjectives add -ier, like happier, hungrier. Rule 4 notes more is used with some adjectives, like more different. Rule 5 lists good and bad as irregular comparatives.