sad
sadder, the saddest
nice
nicer, the nicest
boring
more boring, the most boring
fast
faster, the fastest
expensive
more expensive, the most expensive
happy
happier, the happiest
small
smaller, the smallest
interesting
more interesting, the most interesting
big
bigger, the biggest
popular
more popular, the most popular
old
older, the oldest
cheap
cheaper, the cheapest
slow
slower, the slowest
unpopular
more unpopular, the most unpopular
new
newer, the newest
horrible
more horrible, the most horrible