This article is additional to the main page dedicated to Singular and plural nouns.
Here is a list of irregular nouns that needs to be simply memorized. We devided all irregular nouns into three tables according to levels of English language.
Elementary level
| Singular | Plural |
| child | children |
| foot | feet |
| goose | geese |
| half | halves |
| life | lives |
| loaf | loaves |
| man | men |
| mouse | mice |
| person | people |
| scarf | scarves |
| shelf | shelves |
| thief | thieves |
| tooth | teeth |
| wife | wives |
| wolf | wolves |
| woman | women |
Intermediate level
|
Singular
|
Plural
|
|
appendix
|
appendices
|
|
axis
|
axes
|
|
bacterium
|
bacteria
|
|
basis
|
bases
|
|
cactus
|
cacti or cactus or cactuses
|
|
calf
|
calves
|
|
crisis
|
crises
|
|
criterion
|
criteria
|
|
datum
|
data
|
|
diagnosis
|
diagnoses
|
|
focus
|
foci or focuses
|
|
formula
|
formulae or formulas
|
|
hoof
|
hooves
|
|
hypothesis
|
hypotheses
|
|
index
|
indices or indexes
|
|
medium
|
media or mediums
|
|
matrix
|
matrices
|
|
memorandum
|
memorandums or memoranda
|
|
millennium
|
millennia
|
|
oasis
|
oases
|
|
octopus
|
octopi
|
|
ox
|
ox or oxen
|
|
phenomenon
|
phenomena
|
|
quiz
|
quizzes
|
|
radius
|
radii
|
|
stimulus
|
stimuli
|
|
thesis
|
theses
|
Advanced level
|
Singular
|
Plural
|
|
alumna
|
alumnae
|
|
alumnus
|
alumni
|
|
antithesis
|
antitheses
|
|
apex
|
apices or apexes
|
|
appendix
|
appendices or appendixes
|
|
bacillus
|
bacilli
|
|
bureau
|
bureaux or bureaus
|
|
codex
|
codices
|
|
corpus
|
corpora
|
|
criterion
|
criteria or criterions
|
|
curriculum
|
curricula or curriculums
|
|
die
|
dice or dies
|
|
dwarf
|
dwarves or dwarfs
|
|
ellipsis
|
ellipses
|
|
erratum
|
errata
|
|
genus
|
genera or genuses
|
|
nucleus
|
nuclei or nucleuses
|
|
parenthesis
|
parentheses
|
|
referendum
|
referenda or referendums
|
|
vita
|
vitae
|