To form a regular adverb we simply add –ly to the corresponding adjective‏‎.

slow > slowly

woman > womanly

autonomous > autonomously

However in some cases adding –ly is not a straightforward matter and a few changes are required.

Spelling Rules

• -ic

With adjectives ending in -ic you need to add al before you add -ly

problematic > problematically

scientific > scientifically

automatic > automatically

specific > specifically

Note, an important exception to this rule is PUBLIC > PUBLICLY which of course follows the usual -ly rule of spelling to turn an adjective into an adverb.

• -le

With adjectives ending in –le you need to check first if there is a consonant before –le. If there is, simply change the final e into y.

favorable > favorably

simple > simply

wrinkle > wrinkly

humble > humbly

If instead there is a vowel before –le then simply add -ly to the adjective.

agile > agilely

sole > solely

Exception: with the adjective whole, you need to remove the final e before adding -ly

whole > wholly

• -ll

With adjectives ending in –ll you only need to add -y

dull > dully

full > fully

shrill > shrilly

• -ue

With adjectives ending in –ue you need to drop the final –e before adding -ly

due > duly

true > truly

• -y

With adjectives ending in –y you need to check first if there is a consonant before –y. If there is, simply change the y into i before adding -ly.

busy > busily

uneasy > uneasily

easy > easily

happy > happily

Exception: shy and sly don’t require any changes. Simply add -ly

shy > shyly

sly > slyly

If instead there is a vowel, simply add -ly to the adjective.

coy > coyly

gray > grayly

Exception: with gay you need to change y into i and then add -ly

gay > gaily