The singular and plural forms of some nouns are the same (List)

Certain nouns in the English language exhibit a unique characteristic where their singular and plural forms are identical. This phenomenon contrasts with the typical convention of adding an “s” or “es” to create plural nouns. Examples include “sheep,” “deer,” and “aircraft.” This quirk often leads to confusion among learners of English, as they expect distinct singular and plural forms for most nouns. However, it underscores the rich tapestry of English and its exceptions, which stem from its diverse linguistic roots and evolution over time.

Below you will find a list of English nouns that have the same form in both singular and plural:

SheepSheepA woolly animal
DeerDeerA forest animal
FishFishAquatic animal
AircraftAircraftFlying vehicle
MooseMooseLarge North American mammal
SpeciesSpeciesBiological classification
TroutTroutFreshwater fish
SalmonSalmonAnadromous fish
SwineSwinePigs; a hog
PlanktonPlanktonMicroscopic organisms
AircraftAircraftFlying vehicles
HeadquartersHeadquartersMain office location
CodCodType of fish
BisonBisonLarge mammal
SpacecraftSpacecraftSpace vehicle
ChassisChassisBase frame of vehicle
ShrimpShrimpSmall sea animal
SquidSquidMarine cephalopod
SeriesSeriesSet of items/events
DiceDiceCube with numbers
BarracksBarracksMilitary housing
ChassisChassisVehicle’s base frame
CorpsCorpsMilitary unit/group
HovercraftHovercraftVehicle over surfaces
AircraftAircraftFlying machine
LuggageLuggageBags for traveling
MackerelMackerelSea fish
TunaTunaLarge fish
WatercraftWatercraftBoats and ships
GrouseGrouseType of bird
ReindeerReindeerArctic deer
ShrimpShrimpSmall seafood
SquidSquidMarine creature
WhitingWhitingSmall sea fish
ElkElkLarge deer
MeansMeansMethod or way
SeriesSeriesSequence of events
SpeciesSpeciesClass of individuals
OffspringOffspringChildren or young
AlmsAlmsCharity to the poor
PolicePoliceLaw enforcement
PeoplePeopleGroup of humans
CattleCattleDomestic bovines
PliersPliersTool for grasping
ShortsShortsShort trousers
JeansJeansDenim trousers
WheatWheatCereal plant
ConfettiConfettiSmall pieces or streamers of colored paper
OatsOatsCereal grain
RiceRiceGrain used for food
MathematicsMathematicsStudy of numbers and shapes

In conclusion, the presence of nouns with the same singular and plural forms underscores the complexity and nuance of the English language. These nouns, although exceptions to the typical pluralization rules, serve as reminders of the language’s varied origins and the influence of historical and cultural contexts on its structure. For learners and native speakers alike, they emphasize the need for contextual understanding, rather than relying solely on rigid grammatical patterns.