Collins Cobuild English Grammar (190 page)

However, you do not do this with two-syllable adjectives.

clever		cleverer		the cleverest
stupid		stupider		the stupidest

If an adjective ends in
e
, you remove the
e
when adding
er
or
est
.

wide		wider		the widest
simple		simpler		the simplest

Note that with adjectives ending in
le
, the comparative and superlative have two syllables, not three. For example,
simpler
(from
simple
/′S
I
mpǝl/
) is pronounced
/′S
I
mpǝl/
.

If an adjective ends in a consonant letter followed by
y
, you replace the
y
with
i
when adding
er
or
est
.

dry		drier		the driest
angry		angrier		the angriest
unhappy		unhappier		the unhappiest