Maybe this is a question about forming some plural nouns or some third person singular verbs.
When a noun ends in "y" which follows a consonant (fly, flurry), in order to form the plural, change the "y" to "i" and add "-es." (flies, flurries)
When a verb ends in "y" which follows a consonant (fly, cry, carry, hurry), in order to form the third person singular form of the verb, change the "y" to "i" and add "-es."
(she flies, he cries, she hurries, he carries.)
You have to change the y to an I and add the es
If 'y' is preceded by a consonant, change it to i and add 'es'. If it is preceded by a vowel, don't change it and just add 's'.kitty = kittiesmommy = mommiesvs.monkey = monkeysturkey = turkeys
marry to marries
Some words end in a consonant + y. To make them plural, change y to i and add es. Candy -> Candies
If the verb ends in -s, -sh, -ch, -x, -o, add –es. Examples: kiss = kisses, wash = washesIf the verb ends in a consonant +y, the y changes to –ies. Examples: fly = flies, study = studiesBut if the verb ends in vowel +y, the y does not change. Example: play = plays
You drop the y and add ies to get libraries. You can also say - change the y to an i and add es.
Change the Y to I and add -es : the plural is poppies.
A herd animal that forms the plural by changing the 'y' to 'i' before adding the 'es' is pony - ponies.
This is because of the letters that precede 'Y'. When the 'Y' follows a consonant, the 'Y' must be replaced with 'I' and "ES" is added. When the 'Y' follows a vowel, only an 'S' is needed.
Change the y to an i and add -es.
Most words whose singular ends in "s" form their plural by adding "es". Examples: stress, stresses; fuss, fusses. Some (but not all) words that end with a vowel other than "e" form their plural by adding "es". Examples: tomato, tomatoes; hero, heroes. Words that end with a "y" preceded by a consonant change the "y" to an "i" and add "es". Examples: pony, ponies; pinny, pinnies; tally, tallies.
Mortifies doesn't have a Y because when a word that ends in a Y becomes plural you change the Y to an I and add ES.