THE IRREGULAR PLURAL NOUNS

Irregular plural nouns are nouns that do not become plural by adding -s or -es, as most nouns in the English language do. For example, the plural form of man is men, not mans. The plural form of woman is women, not womans.

Irregular Plural Noun Examples

Aircraft – aircraft

Barracks – barracks

Deer – deer

Gallows – gallows

Moose – moose

Salmon – salmon

Hovercraft – hovercraft

Spacecraft – spacecraft

Series – series

Species – species

Means – means

Offspring – offspring

Deer – deer

Fish – fish

Sheep – sheep

Offspring – offspring

Trout – trout

Swine – swine

Person – people

Ox – oxen

Man – men

Woman – women

Caveman – cavemen

Policeman – policemen

Child – children

Tooth – teeth

Foot – feet

Goose – geese

Mouse – mice

Louse – lice

Penny – pence

Index – indices /indexes

Matrix – matrices

Vertex – vertices

Appendix – appendices

Alumnus – alumni

Corpus – corpora

Census – censuses

Focus – foci

Genus – genera

Prospectus – prospectuses

Radius – radii

Campus – campuses

Succubus – succubi

Some nouns have identical singular and plural. Many of these are the names of animals.

IRREGULAR PLURAL NOUNS LIST:

Aircraft – aircraft

Barracks – barracks

Deer – deer

Gallows – gallows

Moose – moose

Salmon – salmon

Hovercraft – hovercraft

Spacecraft – spacecraft

Series – series

Species – species

Means – means

Offspring – offspring

Deer – deer

Fish – fish

Sheep – sheep

Offspring – offspring

Trout – trout

Swine – swine

NOTE:

The plural is sometimes formed by simply changing the vowel sound of the singular (these are sometimes called mutated plurals):

Irregular Plural Nouns List:

Person – people

Ox – oxen

Man – men

Woman – women

Caveman – cavemen

Policeman – policemen

Child – children

Tooth – teeth

Foot – feet

Goose – geese

Mouse – mice

Louse – lice

Penny – pence

Note: There are many compounds of man and woman that form their plurals in the same way: postmen, policewomen, etc.