A regular plural noun uses the suffixes -s and -es to show more than one person, place, or thing.

Examples

• cat < cats
• dog < dogs
• fox < foxes
• girl < girls

Irregular Plural Nouns

Irregular plural nouns are plural nouns that are not formed by using the suffixes -s or -es. Instead, irregular plural nouns undergo separate changes.

Nouns ending in -f or -fe

To create the plural form of the word ending in -fe you need to replace the f with v then add -es.

• wife < wives
• life < lives
• leaf < leaves

The words roofs and proofs are exceptions to this pattern.

Nouns ending in -o

To create the plural form of the word ending in -o you need to add -es.

• potato < potatoes
• hero < heroes

Exceptions to this pattern exist. Some words ending in -o only need an s to make it plural. Examples include pianos and photos.

Nouns changing vowels

Sometimes vowels change in a word when moving from the singular to the plural tense. To illustrate, oo can change to ee or an can change to en.

• tooth < teeth
• woman < women

Large spelling changes

Some nouns take on huge spelling changes when forming the plural.

• mouse < mice
• ox < oxen

No change plural

We write some nouns the same way whether plural or singular. This includes words like deer, sheep, and fish.

-ex

A noun that ends in -ex usually takes the ending -ice or -xes when forming the plural.

• vortex < vortexes
• index < indices