Spelling Rules for Plural Nouns
Nouns have both singular and plural forms.
Singular means one.
Plural means more than one.
one book   two books
one car   two cars
To make the plural form of most nouns simply add an ~s to the end of the noun. Some nouns require that you change the ending of the word before you add an ~s. Please study the following rules carefully. They will help you learn how to correctly form plural nouns.
If the noun ends with a consonant + ~y, form the plural by changing the ~y to ~i and then add ~es
baby ---> babies
city ---> cities
If the noun ends with a vowel + y, form the plural by adding ~s.
boy ---> boys
day ---> days
If the noun ends with ~ef or ~f, form the plural by changing the ~f to ~v and then add ~s.
wife ---> wives
wolf ---> wolves
If the noun ends with ~sh, ~ch, ~ss, ~x, form the plural by adding ~es
wish ---> wishes
match ---> matches
box ---> boxes
If the noun ends with a consonant + o, form the plural by adding ~es
tomato ---> tomatoes
potato ---> potatoes
If the noun ends in a vowel + o, form the plural by adding ~s
zoo ---> zoos
radio ---> radios