shorter-shortest
taller-tallest
easier-easiest
happier-happiest
more interesting-most interesting
more useful-most useful
more careful-most careful
With most one-syllable adjectives, we add –er or –est, and with most adjectives with two syllables or more, we add more or (the) most. In comparatives, we also use than before the second thing which is compared, if it is mentioned.
Two-syllable adjectives ending in -y change y to i and take the -er and -est endings
