Yellow-yellower-the yellowest
Strange-stranger-the strangest
Attentive-more attentive-the most attentive
Fat-fatter-the fattest
Cheap-cheaper-the cheapest
Pretty-prettier-the prettiest
Experienced-more experienced-the most experienced
Dry-drier-the driest
Fast-faster-the fastest
Little-less-the least
Serious-more serious-the most serious