Comparative and Superlative Adjectives

To make the comparative form of adjectives (like 'bigger' or 'more expensive') and the superlative form (like 'biggest' or 'most expensive'), first we need to know how many syllables are in the adjective.

Adjectives with one syllable

Usually if an adjective has only one syllable, we add 'er' to make the comparative form. We add 'est' to make the superlative form.

clean → cleaner / cleanest
cold → colder / coldest
small → smaller / smallest
young → younger / youngest
tall → taller / tallest

There are some spelling changes. If there is one vowel followed by one consonant at the end of the adjective, we often double the consonant.

wet → wetter / wettest
big → bigger / biggest
hot → hotter / hottest
thin → thinner / thinnest

If the adjective ends in 'y', this often changes to 'i'.

dry → drier / driest

If the adjective ends in 'e', we don't add another 'e', just 'r'.

nice → nicer / nicest
large → larger / largest

Even when the adjective has only one syllable, it's still not wrong to use 'more' or 'most'. It's possible to say 'more wet' or 'most tall'. This isn't incorrect.

There are a few adjectives that we have to use 'more' or 'most' with, even though they only have one syllable. We CAN'T add 'er' or 'est'.

fun → more fun / most fun (NOT ~~funner / funnest~~)
real → more real / most real (NOT ~~realer / realest~~)
right → more right / most right (NOT ~~righter / rightest~~)
wrong → more wrong / most wrong (NOT ~~wronger / wrongest~~)

Adjectives with two syllables

For adjectives with two syllables we generally use 'more' or 'most'.

careful → more careful / most careful
bored → more bored / most bored

But some two syllable adjectives can take 'er' or 'est'. It's also fine to use 'more' (for the comparative) or 'most' (for the superlative).

clever → cleverer / cleverest
simple → simpler / simplest
narrow → narrower / narrowest
quiet → quieter / quietest

Adjectives with two syllables that end in 'y' usually can add 'er' or 'est' (y generally changes to i). It's also fine to use 'more' or 'most'.

dirty → dirtier / dirtiest
pretty → prettier / prettiest
happy → happier / happiest
ugly → uglier / ugliest

Adjectives with more than two syllables

Adjectives with more than two syllables can only make their comparative by using 'more' and their superlative by using 'most'.