Ссравнителем например: hot-hotter-the hottest 1)small,warm,cold,long,short,nice,big; 2)bad,good; 3)interesting,beautiful.

Small - smaller - the smallest
warm-warmer - the warmest
cold - colder - the coldest
long - longer - the longest
short - shorter - the shortest
nice-nicer- the nicest
big - bigger - the biggest
bad - worse- the worst
good - better - the best
interesting - more interesting - the most  interesting
beautiful - more beautiful - the most beautiful