IRREGULAR PLURALS LIST

Study these groups of words to learn how they change to plural. Each group of words has similar changes.

US -> I

SINGULAR PLURAL

alumnus alumni

cactus cacti

focus foci/focuses

fungus fungi/funguses

nucleus Nuclei

radius Radii

stimulus stimuli

IS -> ES

SINGULAR PLURAL

axis Axes

analysis Analyses

basis Bases

crisis Crises

diagnosis Diagnoses

ellipsis Ellipses

hypothesis Hypotheses

oasis Oases

paralysis Paralyses

parenthesis Parentheses

synthesis Syntheses

synopsis Synopses

thesis Theses

IX -> ICES

SINGULAR PLURAL

appendix Appendices

index indeces/indexes

matrix matrices/matrixes

EAU -> EAUX

SINGULAR PLURAL

beau Beaux

bureau bureaus/bureaux

tableau tableaux/tableaus

*** -> EN

SINGULAR PLURAL

child Children

man Men

ox Oxen

woman Women

*** -> A

SINGULAR PLURAL

bacterium Bacteria

corpus Corpora

criterion Criteria

curriculum Curricula

datum Data

genus Genera

medium Media

memorandum memoranda

phenomenon phenomena

stratum Strata

NO CHANGE

SINGULAR PLURAL

deer Deer

fish Fish

means Means

offspring offspring

series Series

sheep Sheep

species Species

OO -> EE

SINGULAR PLURAL

foot Feet

goose Geese

tooth Teeth

A -> AE

SINGULAR PLURAL

antenna antennae/antennas

formula formulae/formulas

nebula nebulae

vertebra vertebrae

vita Vitae

OUSE -> ICE

SINGULAR PLURAL

louse Lice

mouse Mice

The Rules of Regular and Irregular Plurals

For most nouns, just add -sFor nouns ending in s, x, z, ch or sh, add -es

Singular Plural Singular Plural

hand hands box boxes

rabbit rabbits pitch pitches

key keys wish wishes

clock clocks boss bosses

football footballs buzz buzzes

door doors glass glasses

For some words ending in o, add -esHowever, for some words ending in o, just add -s

Singular Plural Singular Plural

potato potatoes cello cellos

tomato tomatoes disco discos

hero heroes hairdo hairdos

echo echoes logo logos

banjo banjoes patio patios

The plural of many words ending in o can be spelt with -s or -es.

photo photos

piano pianos

radio radios

For some words ending in f, change the f to a v and add -es

However, for some words ending in f, just add -s

Singular Plural Singular Plural

half halves chef chefs

loaf loaves cliff cliffs

elf elves ref refs

leaf leaves roof roofs

self selves

The plural of some nouns ending in f can be spelt using either variation.

shelf shelves

thief thieves

wolf wolves

For some nouns ending in ife, change the f to a v and then add -s

For common nouns that end with consonant + y, change the y to an i and then add -es

Singular Plural Singular Plural

wife wives poppy poppies

life lives fly flies

knife knives penny pennies

spy spies

nappy nappies

sty sties

Some nouns are the same in both singular and plural from

For some nouns, change other letters or just change the word completely!

Singular Plural Singular Plural

fish fish person people

sheep sheep child children

deer deer ox oxen

tuna tuna foot feet

salmon salmon tooth teeth

trout trout goose geese

mouse mice

louse lice

man men

    Last updated:  30th September 2006