258. Irregular Plural Nouns

A plural noun names more than one thing. We add -s or -es to a noun to make a regular plural noun.
Here are some regular plural nouns:
dog – dogs
cat – cats

patch – patches
class – classes

An irregular plural noun does not become plural by adding -s or -es.
An irregular plural noun completely changes its spelling when the noun names more than one thing.

Some irregular plural nouns change -oo to -ee:
one foot – two feet
one goose – two geese
one tooth – two teeth

Nouns ending in -f or -fe change to a -v when plural:
half – halves
calf – calves
wife – wives
knife – knives

Nouns ending in -us change to ending in -i when they are plural:
one cactus – many cacti
one fungus – several fungi

Certain nouns become plural with no real pattern for how they change their spelling:
one mouse – three mice
one man – two men
one woman – two women

Irregular plural nouns change their spelling when the noun names more than one thing.

  • It’s your turn. Do you remember how to turn these singular nouns into plural nouns? one foot – two ____ / one mouse – three ______ / one cactus – several ______ How did you do? Did you remember how to write the irregular plural nouns? Good for you!