Form of adverbs

Most adverbs are formed by adding -ly to the end of the related adjective.

slow	slowly
clever	cleverly
annual	annually

Exceptionally, words which end in -ble drop off the -e before -ly is added. So do the words true and due.

sensible	sensibly
suitable	suitably
true	truly
due	duly

A common spelling mistake is to add -ley. This mistake is often made when the adjective ends in the letter -e. Note the correct spelling of adverbs formed from adjectives ending in -e.

extreme	extremely
divine	divinely
free	freely

Adjectives that end in -y change to -i before adding -ly, unless, like sly or dry, they have only one syllable.

happy	happily
greedy	greedily
sly	slyly

Some adverbs keep the same spelling as the adjective to which they are related. It is often difficult to tell at first whether the word is an adjective or an adverb. The general rule is to look at the other words which it occurs with. If it comes before a noun it is probably an adjective.

a short way	a late meeting
a long pause	an early lecture

If it relates to a verb or an adjective it is probably an adverb.

The lesson was cut short.
We met late at night.
Don’t stay long.
He came in early.

Some adverbs have the same spelling as a preposition. They can be told apart if you look at the words they are found with. Prepositions are normally used in front of noun phrases, because prepositions must have an object.

He rushed in an attempt to catch his bus.
She hurried over her meal because she was late.

When the word is found without an object, especially at the end of a clause, it will usually be an adverb.

He rushed in.
She hurried over.

Just like certain adjectives, some adverbs have comparative and superlative forms and can be used with submodifiers.

Kim treated Sharon well, Karen less well and Janice the least well.
Malcolm walked the most slowly of all of them.
Tariq acted very kindly towards him.
You must behave far more sensibly in future.
This graph shows that girls performed the best at maths this year.

Superlative forms of adverbs are quite rare.