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
|