Regular Plural Forms
The majority of English count nouns are regular and predictable in the spelling of the plural form. Add -s to the end of the singular form or -es to those singulars that end in a sibilant sound (/s/, /z/, /ts/, /dz/). -s | -es | ||
boy | boys | horse | horses |
bed | beds | edge | edges |
book | books | patch | patches |
pencil | pencils | prize | prizes |
day | days | box | boxes |
However, if the singular ends with -y and the -y is not preceded by a vowel (or is not a proper name) the -y changes to -i and the plural is then -es.
-y becomes -ies | -y becomes -ys | ||
spy | spies | osprey | ospreys |
poppy | poppies | bay | bays |
penny | pennies | ||
Outside of this pattern, however, are several nouns which are irregular in their spelling. Below is a semi-comprehensive list compiled from various sources.
Irregular Plural Nouns - List One
Some nouns that end in -f or -fe are changed to -ves in the plural: -f or -fe becomes -ves | |
calf | calves |
elf | elves |
half | halves |
hoof | hooves |
knife | knives |
leaf | leaves |
life | lives |
loaf | loaves |
scarf | scarfs/scarves |
self | selves |
sheaf | sheaves |
shelf | shelves |
thief | thieves |
wife | wives |
wolf | wolves |
Irregular Plural Nouns - List Two
Some nouns change the vowel sound in becoming plural: singular | plural |
fireman | firemen |
foot | feet |
goose | geese |
louse | lice |
man | men |
mouse | mice |
tooth | teeth |
woman | women |
Some Old English plurals are still in use:
singular | plural |
child | children |
ox | oxen |
Irregular Plural Nouns - List Three
Some nouns ending in -o take -s as the plural, while others take -es. -o becomes -os | -o becomes -oes | ||
auto | autos | echo | echoes |
kangaroo | kangaroos | embargo | embargoes |
kilo | kilos | hero | heroes |
memo | memos | potato | potatoes |
photo | photos | tomato | tomatoes |
piano | pianos | torpedo | torpedoes |
pimento | pimentos | veto | vetoes |
pro | pros | ||
solo | solos | ||
soprano | sopranos | ||
studio | studios | ||
tattoo | tattoos | ||
video | videos | ||
zoo | zoos | ||
Some nouns ending in -o take either -s or -es:
singular | plural |
buffalo | buffalos/buffaloes |
cargo | cargos/cargoes |
halo | halos/haloes |
mosquito | mosquitos/mosquitoes |
motto | mottos/mottoes |
no | nos/noes |
tornado | tornados/tornadoes |
volcano | volcanos/volcanoes |
zero | zeros/zeroes |
Irregular Plural Nouns - List Four
Some nouns do not change at all: singular | plural |
cod* | cod* |
deer | deer |
fish* | fish* |
offspring | offspring |
perch* | perch* |
sheep | sheep |
trout* | trout* |
*Notice that these are names of fish. Many (but not all!) fish have irregular plural forms. Salmon, pike, halibut and tuna are further examples, but one shark becomes twosharks.
These include nouns that are traditionally plural, but are also used for singular forms: singular | plural |
barracks | barracks |
crossroads | crossroads |
dice/die | dice |
gallows | gallows |
headquarters | headquarters |
means | means |
series | series |
species | species |
Irregular Plural Nouns - List Five
Other nouns retain foreign plurals. Note that some of these have adapted a regular English plural form as well. singular | foreign plural | English plural in use |
alga | algae | |
amoeba | amoebae | amoebas |
antenna | antennae | antennas |
formula | formulae | formulas |
larva | larvae | |
nebula | nebulae | nebulas |
vertebra | vertebrae |
Nouns ending in -us with plural -a (only in technical use):
singular | plural |
corpus | corpora |
genus | genera |
Nouns ending in -us with plural -i:
singular | foreign plural | English plural in use |
alumnus | alumni | |
bacillus | bacilli | |
cactus | cacti | cactuses |
focus | foci | |
fungus | fungi | funguses |
nucleus | nuclei | |
octopus | octopi | octopuses |
radius | radii | |
stimulus | stimuli | |
syllabus | syllabi | syllabuses |
terminus | termini |
Nouns ending in -um with plural -a:
singular | Foreign plural | English plural in use |
addendum | addenda | |
bacterium | bacteria | |
curriculum | curricula | curriculums |
datum | data | |
erratum | errata | |
medium | media | |
memorandum | memoranda | memorandums |
ovum | ova | |
stratum | strata | |
symposium | symposia | symposiums |
Nouns ending in -ex, -ix becoming plural -ices:
singular | Foreign plural | English plural in use |
apex | apices | apexes |
appendix | appendices | appendixes |
cervix | cervices | cervixes |
index | indices | indexes |
matrix | matrices | matrixes |
vortex | vortices |
Nouns ending in -is becoming -es in plural:
singular | plural |
analysis | analyses |
axis | axes |
basis | bases |
crisis | crises |
diagnosis | diagnoses |
emphasis | emphases |
hypothesis | hypotheses |
neurosis | neuroses |
oasis | oases |
parenthesis | parentheses |
synopsis | synopses |
thesis | theses |
Nouns ending in -on becoming -a:
singular | plural |
criterion | criteria |
phenomenon | phenomena |
automaton | automata |
Other irregular plurals, retained from different languages:
singular | plural | |
Italian | libretto | libretti |
tempo | tempi | |
virtuoso | virtuosi | |
Hebrew | cherub | cherubim |
seraph | seraphim | |
Greek | schema | schemata |
