English plurals

In the English language, nouns are inflected for grammatical number—that is, singular or plural. This article discusses the variety of ways in which English plurals are formed. Phonetic transcriptions, given inside slashes, are in SAMPA notation.

Regular plurals

The plural morpheme in English is suffixed to the end of most nouns. The plural form is usually represented orthographically by adding -s to the singular form (see exceptions below). The phonetic form of the plural morpheme is /z/ by default. When the preceding sound is a voiceless consonant (see phonation), it is pronounced /s/. Examples:

boy           boys
girl          girls
cat           cats
chair         chairs

Where a noun ends in a sibilant sound—such as s, sh, x, soft ch—the plural is formed by adding es (also pronounced as z with a neutral vowel sound or short i):

glass         glasses
dish          dishes
witch         witches

Morphophonetically, these rules are sufficient to describe most English plurals. However, there are several complications introduced in spelling.

The -oes rule: most nouns ending in o preceded by a consonant also form their plurals by adding -es (pronounced /z/):

hero          heroes
potato        potatoes
volcano       volcanoes

The -ies rule: nouns ending in a y preceded by a consonant drop the y and add -ies (pronounced /:iz/):

cherry        cherries
lady          ladies

Note, however, that proper nouns (particularly those for people or places) ending in a y preceded by a consonant form their plurals regularly:

Harry         Harrys (as in There are three Harrys in our office)
Germany       Germanys (as in The two Germanys were unified in 1990)

This does not apply to words that are merely capitalised common nouns:

P&O Ferries (from ferry)

A few common nouns ending in a y preceded by a consonant form their plurals regularly:

henry         henrys
zloty         zlotys

Almost-regular plurals

Many nouns of Italian or Spanish origin are exceptions to this rule:

canto         cantos
grotto        grottos
piano         pianos
portico       porticos
quarto        quartos
solo          solos

Most nouns ending in f or fe form their plurals by changing the f into a v and adding es:

calf          calves
half          halves
wolf          wolves
wharf         wharves
life          lives

Some just add an s:

proof         proofs
muff          muffs

Some can do either:

dwarf         dwarfs / dwarves
hoof          hoofs / hooves
staff         staffs / staves
turf          turfs / turves (latter rare)
roof          roofs / rooves / roovis  (latter two archaic)

• Dwarf is an interesting case: the common form of the plural was dwarfs—as, for example, in Walt Disney's Snow White and the Seven Dwarfs—until J. R. R. Tolkien popularised dwarves, perhaps for its old-fashioned sound. Multiple dwarf stars, or non-mythological short human beings, however, are dwarfs.
• Staff in the sense of "a body of employees" the plural is always staffs; otherwise both staffs and staves are acceptable, except in compounds; such as flagstaffs. The stave of a barrel or cask is a back-formation from staves, which is its plural. (See below for another kind of back-formed plural.)

Irregular plurals

There are many other less regular ways of forming plurals. While they may seem quirky, they usually stem from older forms of English or from foreign borrowings.

Irregular Germanic plurals

The plural of a few Germanic nouns can also be formed from the singular by adding n or en, stemming from the obsolete dual:

ox            oxen    (also oxes, properly oxen only refers to a pair)
cow           cyne    (rare/regional, properly cyne only refers to a pair)
eye           eyen    (Rare, found in some regional dialects)
shoe          shoon   (Also rare/obsolete)

The word box, referring to a computer, is semi-humorously pluralized boxen in the Leet dialect. Multiple Vax computers, likewise, are sometimes called Vaxen.

The plural is sometimes formed by simply changing the vowel sound of the singular, in a process called ablaut (these are sometimes called mutated plurals):

foot          feet
goose         geese
louse         lice
man           men
mouse         mice
tooth         teeth
woman         women

Some nouns have singular and plural alike, although they are sometimes seen as regular plurals:

sheep
deer
cod
series
trout

Irregular plurals of foreign origin

Because English includes words from so many ancestral languages, as well as many loanwords from Classical Greek and Latin and other modern languages, there are many other forms of plurals. Such nouns often retain their original plurals, at least for some time after they are introduced. In some cases both forms are still vying for attention: for example, for a librarian, the plural of appendix is appendices (following the original language); for physicians, however, the plural of appendix is appendixes. Likewise, a radio engineer works with antennas and an entomologist deals with antennae. The "correct" form is the one that sounds better in context, or that people in the field use.

Correctly formed Latin plurals are the most acceptable, and indeed are often required, in academic and scientific contexts. In common usage, back-formed plurals are sometimes preferred. (See below for another kind of back-formed plural.)

• Final a becomes ae (strictly æ)—or just adds s:

formula        formulae / formulas
alumna         alumnae

• Final ex becomes ices— or just adds es:

vertex         vertices
index          indices / indexes

• Final is becomes es:

axis          axes
testis        testes 
crisis        crises

• Final on becomes a:

phenomenon     phenomena (more below)
criterion      criteria
automaton      automata
polyhedron     polyhedra

• Final um becomes a – or just adds s

addendum       addenda
memorandum     memoranda / memorandums
medium         media

• Final us becomes i (second declension) or era or ora (third declension)—or just adds es (especially in fourth declension, where it would otherwise be the same as the singular):

radius         radii
alumnus        alumni
viscus         viscera
corpus         corpora

Note: See article on the Plural of virus.

• Final as in one case of a noun of Greek origin changes to antes:

Atlas         Atlantes (statues of the hero); but
atlas         atlases (map collections)

• Final ma in nouns of Greek origin add ta:

stigma        stigmata
stoma         stomata
zeugma        zeugmata

Though some take s more commonly:

schema        schemata / schemas
dogma         dogmata / dogmas

• Final us in nouns of Greek origin "properly" add es. These words are also heard with the Latin -i instead, which is sometimes considered "over-correct", but this is so common as to be acceptable in most circumstances, even technical ones.

cactus         cactuses / cacti
hippopotamus   hippopotamuses / hippopotami
octopus        octopuses
platypus       platypuses
rhinoceros     rhinoceroses / rhinoceri

The Greek plural for words ending in -pus meaning "foot", is podes, but this plural is not used in English.

• Some nouns of French origin add x

beau           beaux 
chateau        chateaux

• Nouns of Hebrew language origin add im or ot (generally m/f)—or just s
  Note that ot is pronounced os in the Ashkenazi dialect.

cherub         cherubim / cherubs
seraph         seraphim / seraphs
matzoh         matzot / matzos

• Nouns of Japanese origin have no plural and do not change:

kimono         kimono
samurai        samurai
otaku          otaku

Note: kimonos, following the French model, is now generally accepted in English.

Nouns from languages that have donated few words to English, and that are spoken by relatively few English-speakers, generally form plurals as if they were native English words:

canoe            canoes
kayak            kayaks
igloo            igloos
cwm              cwms (Welsh valley)

Some words of foreign origin are much better known in the plural; usage of the proper singular may be considered pedantic or actually incorrect by some speakers. In common usage, the proper plural is considered the singular form. Back-formation has usually resulted in a regularized plural.

Proper singular   Proper plural/    Common plural
                  common singular

candelabrum       candelabra        candelabras
datum             data              data (mass noun)
agendum           agenda            agendas / (less common) agendae
graffito          graffiti          graffiti (mass noun)
insigne           insignia          insignias
alga              algae             algae / algaes
opus              opera             operas
viscus            viscera           (singular not in common usage)
phalanx           phalanges         

Note: A single piece of data is often referred to as a data point. A military phalanx is pluralized phalanxes. The phalanges as body parts (fingers and toes) are rarely referred to in the singular.

A related phenomenon is the confusion of a foreign plural for its singular form:

phenomenon        phenomena
criterion         criteria
symposium         symposia

Plurals of numbers

Plurals for the names of numbers differ according to how they are used. Such words include dozen, hundred, thousand, million, and so forth. The following examples apply to all of these.

• When modified by a number, the plural is not inflected, that is, has no s added. Hence one hundred, two hundred , etc. For vaguer large numbers, one could say several hundred, but many hundreds.

• When used alone, or followed by a prepositional phrase, the plural is inflected: dozens of complaints. However, either complaints by the dozen or complaints by the dozens is acceptable.
• The preposition of is used when speaking of non-specific items identified by pronouns: two hundred of these, three dozen of those. The of is not used for a number of specific items: three hundred oriental rugs. However, if the pronoun is included with the specific item, the of is used: five million of those dollar bills.

Defective nouns

Some nouns have no singular form:

annals              billiards           cattle
measles             nuptials
thanks              tidings             victuals / vittles

Note, however, that billiard as a singular is used as a number in some versions of British English for 10¹⁵ (others will call this a thousand billion or quadrillion), but when speaking of the table game, only exists as plural. These words do have non-noun forms that do not end in s. For example, thank you or billiard ball.

Neither do some names of things having two parts:

scissors
trousers
tweezers
pants

Note, however, that these words are interchangeable with a pair of scissors, a pair of trousers, and so forth. Nor are scissor, trouser, tweezer, or pant the names of the individual parts. However, the fashion industry frequently calls a single pair of pants a pant; this is a back-formation. (See below for another kind of back-formed plural.)

Some words in which the modifier follows the noun form the plural inside the word or phrase, particularly legal terms from French:

attorney general       attorneys general
son-in-law             sons-in-law
court martial          courts martial
armful                 armsful / armfuls (the latter is preferred today)
governor-general       governors-general  
Knight Hospitaller     Knights Hospitallers
agent provocateur      agents provocateurs

It is common in informal speech to pluralise the last word in the usual way, but in edited prose, the forms given are preferred.

Non-countable, or "mass" nouns do not represent distinct objects, so the singular and plural semantics do not apply in the same way. Some examples:

• Abstract nouns

goodness            idleness            wisdom
deceit              honesty             freshness

• Arts and sciences (even those ending in ics are treated as singular)

chemistry           geometry            surgery
biometrics          mechanics           optics
blues (music)

• Other non-countable nouns, such as chemical elements and substances:

antimony            gold                oxygen
equipment           furniture           specie              distress
sand                water               air                 informations

Some mass nouns can be pluralized, but the meaning thereof may change slightly. For example, when I have two pieces of sand, I do not have two sands; I have sand. There is more sand in your pile, not more sands. But there could be many "sands of Africa" - either many distinct stretches of sand, or distinct types of sand of interest to geologists or builders, or simply the allusive sands of Africa.

It is rare to pluralize furniture in this way. Nor would information be so treated, except in the case of criminal informations, which are prosecutor's briefs similar to indictments.

There is only one class of atoms called oxygen, but there are several isotopes of oxygen, which might be referred to as different oxygens. In casual speech, oxygen might be used as shorthand for "oxygen atoms", but in this case it is not a mass noun, so it is entirely sensible to refer to multiple oxygens in the same molecule.

One would interpret "Bob's wisdoms" as various pieces of Bob's wisdom (that is, pieces of advice), deceits as a series of instances of deceitful behavior, and the different idlenesses of the worker as plural distinct manifestations of the mass concept of idleness (or as different types of idleness, "bone lazy" versus "no work to do").

• Specie and species make a fascinating case. Both words come from a Latin word meaning "kind", but they do not form a singular-plural pair; they are separate non-countable nouns. Coins, such as nickels, euros, and cents are specie, but there is no plural. The idea is "payment in kind". And species, the "kinds of living things", is the same in singular and plural.
• Some names of elements, such as nickel, have plurals in non-chemical uses, as "five nickels to the quarter".

Nouns with multiple plurals

Some nouns have two plurals, one used to refer to a number of things considered individually, the other to refer to a number of things collectively. In some cases, one of the two is nowadays archaic or dialectal.

brother             brothers            brethren
cannon              cannons             cannon
child               children            childer*
cow                 cows                kine*
die                 dice                dies
fish                fish                fishes*
penny               pennies             pence*
sow                 sows                swine
pig                 pigs                swine 
iris                iris                irises*
cloth               cloths              clothes*             

• Childer has all but disappeared, but can still be seen in Childermas (Innocents' Day).
• Kine is still used in rural English dialects.
• Dies is used as the plural for die in the sense of a mould; dice as the plural (and increasingly as the singular) in the sense of a small random number generator.
• Fish: the plural for one species of fish, or caught fish, is fish, but for live fish of many species, or in poetic usage, fishes is used.
• If you have several (British) one-penny pieces you have several pennies. Pence is used for an amount of money, which can be made up of a number of coins of different denominations: one penny and one five-penny piece are together worth six pence. Penny and pennies also refer to one or more U.S. one-cent pieces. But in American usage, a nickel is worth five cents, not five pence, though a penny is worth one cent (not plural).
• For multiple plants, say iris, but for multiple blossoms say irises.
• Clothes refers collectively to all of the cloth covering a person's body.

A final odd case is person. The word people is usually treated as the suppletive plural of person (one person, many people). However, in legal and other formal contexts, the plural of person is persons; furthermore, people can also be a singular noun with its own plural (for example, "We are many persons, from many peoples").

Symbols and abbreviations whose plural would be ambiguous if only an s were added are pluralized by adding 's.

  mind your p's and q's  

Regular words and non-ambiguous abbreviations (like PCs or ICBMs) should be pluralized in the normal way, not with an apostrophe, lest they be confused with the possessive.

Plurals of "headless" nouns

Linguist Steven Pinker, in his book, The Language Instinct discusses what he calls "headless words", that is, words like low-life and Red Sox where the life and sox are not being used in their ordinary senses; that is, a low-life is not a type of life, nor are Red Sox a kind of sock. Thus, more than one low-life is low-lifes and a single member of the Boston baseball team is a Red Sox. Other examples include the ice-hockey Maple Leafs, not Maple Leaves, sabertooth and sabertooths, flatfoot and flatfoots, tenderfoot and tenderfoots, still life and still lifes.

The computer mouse is often pluralized mouses, although, in this case, mice is just as common because of the physical similarity between the input device and the rodent.

Plural to singular by back formation

Some words have started out with unusually formed singulars and plurals, but more "normal" singular-plural pairs have resulted. For an example from the vegetable world, pease was the singular and peasen the plural, but over the centuries, first pease became the plural and pea the singular, and finally the plural was altered to peas. Similarly, termites and primates were the three-syllable plurals of termes and primas, respectively, but these singulars were lost, the plurals given two syllables, and now we have termite and termites and primate and primates. Syringe is a back formation from syringes, itself the plural of syrinx, a musical instrument. Cherry is from Norman French cherise. Finally, phases was once the plural of phasis, but the singular is now phase.

Kudos is a singular Greek word meaning praise, but the same process may be happening to it. At present, kudo is an error, however.

Plurals of names of peoples

There are several different rules for this.

In discussing peoples whose demonym takes -man or -woman, there are two options: pluralize to -men or -women if referring to individuals, and use the root alone if referring to the whole nation.

Englishman       Englishmen        the English
Frenchwoman      Frenchwomen       the French
Dutchman or      Dutch people      the Dutch
    Dutchwoman

This also applies to the Irish and the Welsh. One can say "a Scots(wo)man" or "a Scot", "Scots(wo)men", "Scottish people", or "Scots," and "the Scottish" or "the Scots". (Scotch is considered old fashioned.)

Several peoples have names that are simple nouns and can be pluralized:

Dane             Danes             the Danes (or) the Danish
Finn             Finns             the Finns (or) the Finnish
Swede            Swedes            the Swedes (or) the Swedish
Spaniard         Spaniards         the Spaniards (or) the Spanish 
                                               (much more common)

Names of peoples that end in -ese take no plural:

Chinese          Chinese           the Chinese
                   (or Chinese people)

Neither do Swiss or Québécois.

Most names for American Aboriginal groups are not pluralized:

Ojibwa           Ojibwa
Iroquois         Iroquois
Blood            Blood
Mi'kmaq          Mi'kmaq

Some exceptions include Crees, Mohawks, Hurons, Algonquins, Chippewas, Oneidas, Aztecs. Note also the following words borrowed from Inuktitut:

Inuk             Inuit
Nunavummiuq      Nunavummiut
Iqalummiuq       Iqalummiut
Nunavimmiuq          Nunavimmiut
inukshuk         inukshuit

Names of most other peoples of the world are pluralized using the normal English rules.