For adjectives that are just one syllable, add -er to the end
FAST-ER / SMART-ER / LONG-ER
For two-syllable adjectives ending in -y, change the -y to -i and add -er.
HAPP-IER / FUNN-IER
For two-syllable adjectives not ending in -y and for all three-or-more-syllable adjectives, use the form “more + adjective.”
MORE BORING / MORE EXCITING