REMEMBER: add -er:
With adjectives of 1 syllable
*adjectives that end in -e we add only -r
adjectives that end in a vowel sandwich (consonant-vowel-consonant), we double the final consonant: hot-hotter; thin-thinner
with adjectives of 2 syllables ending in -y, we change the y to i and add -er: lucky-luckier; crazy-crazier