Comparative adjectives are forms of adjectives used to compare the qualities of two or more nouns. In English, the most common way to mark comparison is by adding -er to the adjective or by using more before the adjective. The choice depends on the length and structure of the adjective. The comparison usually connects the two items being compared with words like than or leaves the comparison implicit.

For most adjectives with one syllable, form the comparative by adding -er to the base adjective. If the adjective ends in a single consonant with a single vowel before it, double the final consonant before adding -er. If the adjective ends in -e, add only -r. These rules create forms like taller, bigger, and nicer.

Rule
For most one-syllable adjectives, add -er to form the comparative.
If a one-syllable adjective ends with a single vowel followed by a single consonant, double the consonant and add -er.
If a one-syllable adjective ends in -e, add -r to form the comparative.

For adjectives with two syllables that end in -y, form the comparative by changing -y to -i and adding -er. This pattern covers words like happy, busy, and early. The result is forms like happier, busier, and earlier.

Rule
For two-syllable adjectives ending in -y, change -y to -i and add -er.

For most adjectives with two or more syllables that do not end in -y, form the comparative with more before the adjective. The adjective itself does not change spelling in this pattern. This rule covers words like careful, modern, and interesting.

Rule
For adjectives with two or more syllables not ending in -y, use more before the adjective to form the comparative.

Some common adjectives have irregular comparative forms that do not follow the regular -er or more patterns. These forms must be learned as fixed pairs. They are among the most frequent comparatives in English.

Word/Phrase	Definition
good ➡️ better	The comparative of good is better.
bad ➡️ worse	The comparative of bad is worse.
far ➡️ farther	The comparative of far is farther, often used for physical distance.
far ➡️ further	The comparative of far is further, often used for extension or degree.

Comparative adjectives in English use -er for most short adjectives, -ier for two-syllable adjectives ending in -y, and more for most longer adjectives. A small set of adjectives is irregular and must be memorized. The comparative form allows you to compare qualities between nouns clearly and correctly.