Rules, Exceptions and Examples

There are many plural noun rules, and it’s important to know all of them!. It usually  depends on what letter the singular noun ends in.

1. In general we add  ‑S to the end of the noun to form the plural. 

cat – cats

house – houses

car - cars
2. If the singular noun ends in ‑s, -ss, -sh, -ch, -x, or -z, add ‑ES to the end to form  the plural.

kiss  – kisses

bus – buses

dish – dishes

sandwich  – sandwiches

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

leaf - leaves

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 -y per -i and add -es  to form the noun plural.

city – cities

puppy – puppies

baby - babies

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

ray – rays

boy – boys

7 If the singular noun ends in ‑o, and before there’s a consonant  add ‑es to form the 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:

Mark caught one fish, but I caught three fish.

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

Now take those two quizzes

EXERCISE 1

Choose the best option

EXERCISE 2

Choose the correct answer