true—truly
due—duly
whole—wholly
b. When the last syllable of a word ends in "le," "ly" does not make a new syllable, as: probable—-probably, possible—possibly, simple—simply.
(When "ly" is added to words ending in "l," both "l's" are retained, as: practical—practically, careful—carefully.)
IV. Treatment of the final "y"
1. To form the plural of a noun ending in "y" preceded by a consonant, change the "y" to "i" and add "es."
lady—ladies
quantity—quantities
quality—qualities
2. When a verb ends in "y" preceded by a consonant, change the "y" to "i" and add "es" to form the third person singular of the verb. To form the past tense of the verb, change the "y" to "i" and add "ed."
fry—fries
cry—cries
bury—buried
carry—carried
3. When a word ends in "y" preceded by a vowel, form the plural by adding "s."
turkey—turkeys
chimney—chimneys
valley—valleys