Fit
fitter - the fittest
Bad
worse - the worst
Ugly
uglier - the ugliest
Funny
funnier - the funniest
High
higer - the higest
Fat
fatter - the fattest
Short
shorter - the shortest
Cold
colder - the coldest
Thin
thinner - the thinnest
Wide
wider - the widest
Dark
darker - the darkest
Tall
taller - the tallest
Happy
happier - the happiest
Heavy
heavier - the heaviest
Small
smaller - the smallest
Good
better - the best
Pretty
prettier - the prettiest
Busy
busier - the busiest
Clear
clearer - the clearest
Wise
wiser - the wisest
Simple
simpler - the simplest
Fast
faster - the fastest
Hot
hotter - the hottest
Big
bigger - the biggest