Comparative and Superlative Adjectives

The Tower of London is older than the Empire State Building.
There are 3 rules regarding the comparative and superlative forms of adjectives:

1. For short adjectives (adjectives with 1 syllable) we add -er in the comparative form and -est in the superlative form:

Short adjective

Comparative

Superlative

small
tall
cheap
long

smaller than
taller than
cheaper than
longer than

the smallest
the tallest
the cheapest
the longest

Examples:

Comparatives

France is smaller than Argentina.
Cheese is cheaper than caviar.
The Tower of London is older than the Empire State Building.

Superlatives

Yesterday was the hottest* day of the year.
The Mississippi is the longest river in America.
Bill Gates is one of the richest men in the world.

* Note that when the last 3 letters of a word are consonant – vowel – consonant in that order, when we add extra letters, the last letter becomes a double:

Adjective

Comparative

Superlative

big
hot
fat

bigger than
hotter than
fatter than

the biggest
the hottest
the fattest

2. For adjectives which end with y, short and long, we replace the y with ier in the comparative form and iest in the superlative form:

Adjective

Comparative

Superlative

happy
heavy
lucky
friendly

happier than
heavier than
luckier than
friendlier than

the happiest
the heaviest
the luckiest
the friendliest

Examples:

Comparatives

Iron is heavier than wood.
He is friendlier than his mother.
She is prettier than her sister.

Superlatives

He is the happiest man I know.
This is the dirtiest room in the house.
You are the luckiest person in the world.

3. For long adjectives (with more than 1 syllable) which don’t end with y, the adjective remains the same and we add more in the comparative and the most in the superlative form:

Long adjective

Comparative

Superlative

interesting
dangerous
beautiful
expensive

more interesting than
more dangerous than
more beautiful than
more expensive than

the most interesting
the most dangerous
the most beautiful
the most expensive

Examples:

Comparatives

The Da Vinci Code is more interesting than Angels and Demons.
The World Cup final of 1978 was more exciting than the World Cup final of 1990.
Tokyo is more expensive than New York.

Superlatives

She is the most beautiful girl I know.
That was the most exciting match of the year.
London is the most interesting city in England.

So there are 3 rules. There are also 3 exceptions:

Irregular adjective

Comparative

Superlative

good
bad
far

better than
worse than
farther than / further than

the best
the worst
the farthest / the furthest

Examples:

Comparatives

The first Ice Age film was better than the second one.
The third Ice Age film was worse than the second one.
I got lost. The hotel was further than I thought.

Superlatives

Back to the Future is the best film I’ve seen.
That was the worst song of the concert.
25 miles is the farthest I’ve run in one day.

Note that we can say:

Tokyo is more expensive than Los Angeles.

Or

Los Angeles is less expensive than Tokyo.

If we use less, the adjective remains in its original form:

This shop is less cheap than that one.
She is less friendly than her sister.

When two things are the same we use as:

He is as tall as me.
Brad Pitt is as handsome as George Clooney.

Similarily, if we make a negative sentence, we can use as to say two things aren’t the same:

Italy isn’t as cheap as Argentina.
This team isn’t as good as last year’s team.