Plural Nouns: Rules and Examples

Most singular nouns are made plural by simply putting an -s at the end. There are many different rules regarding pluralization depending on what letter a noun ends in. Irregular nouns do not follow plural noun rules, so they must be memorized or looked up in the dictionary.

Plural Noun Rules

There are many plural noun rules, and because we use nouns so frequently when writing, it’s important to know all of them! The correct spelling of plurals usually depends on what letter the singular noun ends in.

1 To make regular nouns plural, add ‑s to the end.

cat – cats

house – houses

2 If the singular noun ends in ‑s, -ss, -sh, -ch, -x, or -z, add ‑es to the end to make it plural.

truss – trusses

bus – buses

marsh – marshes

lunch – lunches

tax – taxes

blitz – blitzes

3 In some cases, singular nouns ending in -s or -z, require that you double the -s or -z prior to adding the -es for pluralization.

fez – fezzes

gas –gasses

4 If the noun ends with ‑f or ‑fe, the f is often changed to ‑ve before adding the -s to form the plural version.

wife – wives

wolf – wolves

Exceptions:

roof – roofs

belief – beliefs

chef – chefs

chief – chiefs

5 If a singular noun ends in ‑y and the letter before the -y is a consonant, change the ending to ‑ies to make the noun plural.

city – cities

puppy – puppies

6 If the singular noun ends in -y and the letter before the -y is a vowel, simply add an -s to make it plural.

ray – rays

boy – boys

7 If the singular noun ends in ‑o, add ‑es to make it plural.

potato – potatoes

tomato – tomatoes

Exceptions:

photo – photos

piano – pianos

halo – halos

With the unique word volcano, you can apply the standard pluralization for words that end in -o or not. It’s your choice! Both of the following are correct:

volcanoes

volcanos

8 If the singular noun ends in ‑us, the plural ending is frequently ‑i.

cactus – cacti

focus – foci

9 If the singular noun ends in ‑is, the plural ending is ‑es.

analysis – analyses

ellipsis – ellipses

10 If the singular noun ends in ‑on, the plural ending is ‑a.

phenomenon – phenomena

criterion – criteria

11 Some nouns don’t change at all when they’re pluralized.

sheep – sheep

series – series

species – species

deer –deer

You need to see these nouns in context to identify them as singular or plural. Consider the following sentence:

Plural Noun Rules for Irregular Nouns

Irregular nouns follow no specific rules, so it’s best to memorize these or look up the proper pluralization in the dictionary.

child – children

goose – geese

man – men

woman – women

tooth – teeth

foot – feet

mouse – mice

person – people