English plurals

English nouns are inflected for grammatical number, meaning that if they are of the countable type, they generally have different forms for singular and plural. This article discusses the variety of ways in which English plural nouns are formed from the corresponding singular forms, as well as various issues concerning the usage of singulars and plurals in English. For plurals of pronouns, see English personal pronouns.

Phonological transcriptions provided in this article are for Received Pronunciation and General American. For more information, see English phonology.

Regular plurals

The plural morpheme in English is suffixed to the end of most nouns. Regular English plurals fall into three classes, depending upon the sound that ends the singular form:

Where a singular noun ends in a sibilant sound —/s/, /z/, /ʃ/, /ʒ/, /tʃ/ or /dʒ/— the plural is formed by adding /ɪz/ or /əz/ (in some transcription systems, this is abbreviated as /ᵻ/). The spelling adds -es, or -s if the singular already ends in -e:

kiss	kisses	/ˈkɪsᵻz/
phase	phases	/ˈfeɪzᵻz/
dish	dishes	/ˈdɪʃᵻz/
massage	massages	/məˈsɑːʒᵻz/ or /ˈmæsɑːʒᵻz/
witch	witches	/ˈwɪtʃᵻz/
judge	judges	/ˈdʒʌdʒᵻz/

When the singular form ends in a voiceless consonant (other than a sibilant) —/p/, /t/, /k/, /f/ (sometimes) or /θ/— the plural is formed by adding /s/. The spelling adds -s:

lap	laps	/læps/
cat	cats	/kæts/
clock	clocks	/klɒks/
cuff	cuffs	/kʌfs/
death	deaths	/dɛθs/

For all other words (i.e. words ending in vowels or voiced non-sibilants) the regular plural adds /z/, represented orthographically by -s:

boy	boys	/bɔɪz/
girl	girls	/ɡɜːrlz/
chair	chairs	/tʃɛərz/

Phonologically, these rules are sufficient to describe most English plurals. However, certain complications arise in the spelling of certain plurals, as described below.

Plurals of nouns in -o

With nouns ending in o preceded by a consonant, the plural in many cases is spelled by adding -es (pronounced /z/):

hero	heroes
potato	potatoes
volcano	volcanoes or volcanos

However many nouns of foreign origin, including almost all Italian loanwords, add only -s:

canto	cantos
hetero	heteros
photo	photos
zero	zeros
piano	pianos
portico	porticos
pro	pros
quarto (paper size)	quartos
kimono	kimonos

Plurals of nouns in -y

Nouns ending in a y preceded by a consonant usually drop the y and add -ies (pronounced /iz/, or /aiz/ in words where the y is pronounced /ai/):

cherry	cherries
lady	ladies
sky	skies

Words ending in quy also follow this pattern:

soliloquy

soliloquies

However, nouns of this type which are proper nouns (particularly names of people) form their plurals by simply adding -s:^{[references 1][references 2]} the two Kennedys, there are three Harrys in our office. With place names this rule is not always adhered to: Germanys and Germanies are both used,^{[references 3]} and Sicilies and Scillies are the standard plurals of Sicily and Scilly. Nor does the rule apply to words that are merely capitalized common nouns: P&O Ferries (from ferry).

Other exceptions include lay-bys and stand-bys.

Words ending in a y preceded by a vowel form their plurals by adding -s:

day	days
monkey	monkeys

However the plural form (rarely used) of money is usually monies, although moneys is also found.^{[references 4]}

Near-regular plurals

In Old and Middle English voiceless fricatives /f/, /θ/ mutated to voiced fricatives before a voiced ending.^{[references 5]} In some words this voicing survives in the modern English plural. In the case of /f/ changing to /v/, the mutation is indicated in the orthography as well; also, a silent e is added in this case if the singular does not already end with -e:

bath	baths	/bɑːðz/, /bæðz/
mouth[a 1]	mouths	/maʊðz/
calf	calves	/kɑːvz/, /kævz/
leaf[a 2]	leaves	/liːvz/
knife[a 1]	knives	/naɪvz/
life	lives	/laɪvz/

In addition, there is one word where /s/ is voiced in the plural:^{[references 5]}

house[a 1]

houses

/haʊzᵻz/

Many nouns ending in /f/ or /θ/ (including all words where /f/ is represented orthographically by gh or ph) nevertheless retain the voiceless consonant:

moth	moths (voiced /mɒðz/ is rare but does occur in New England and Canada)
proof	proofs

Some can do either:

dwarf[a 3]	dwarfs/dwarves
hoof	hoofs/hooves
elf	elfs/elves
roof	roofs (commonly voiced as /ruːvz/ to rhyme with hooves, but rooves is a rare archaic spelling)
staff[a 4]	staffs/staves
turf	turfs/turves (latter rare)

Irregular plurals

There are many other less regular ways of forming plurals, usually stemming from older forms of English or from foreign borrowings.

Nouns with identical singular and plural

Some nouns have identical singular and plural. Many of these are the names of animals:

bison

buffalo

deer

duck^{[a 5]}

fish

moose

pike

plankton

salmon

sheep

squid

swine

trout

The plural deers is listed in some dictionaries.^{[references 6]} As a general rule, game or other animals are often referred to in the singular for the plural in a sporting context: "He shot six brace of pheasant", "Carruthers bagged a dozen tiger last year", whereas in another context such as zoology or tourism the regular plural would be used. Eric Partridge refers to these sporting terms as "snob plurals" and conjectures that they may have developed by analogy with the common English irregular plural animal words "deer", "sheep" and "trout".^{[references 7]} Similarly, nearly all kinds of fish have no separate plural form (though there are exceptions—such as rays, sharks or lampreys). As to the word fish itself, the plural is usually identical to the singular, although fishes is sometimes used, especially when meaning "species of fish". Fishes is also used in iconic contexts, such as the Bible story of the loaves and fishes, or the reference in The Godfather, "Luca Brasi sleeps with the fishes."

Other nouns that have or may have identical singular and plural forms include:

aircraft; watercraft; spacecraft; hovercraft; ocean-going craft

the blues^{[a 6]}

cannon (sometimes cannons)^{[a 7]}

head^{[a 8]}

iris (usually irises, but iris can be the plural for multiple plants; in medical contexts irides is used)

stone - as a unit of weight equal to 14 pounds (occasionally stones)^{[a 9]}

series, species (and other words in -ies)

counsel (barrister, lawyer, opinion/advice)

Notes:

1. In a Canadian accent, the mutation to a voiced consonant produces a change in the sound of the preceding diphthong (/aʊ/ or /aɪ/).
2. The Toronto Maple Leafs ice hockey team is a special case; see Teams and their members below.
3. For dwarf, 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 popularized dwarves; he intended the changed spelling to differentiate the "dwarf" fantasy race in his novels from the cuter and simpler beings common in fairy tales, but his usage has since spread. Multiple astronomical dwarf stars and multiple nonmythological short human beings, however, remain dwarfs.
4. For staff (/stæf/ or /stɑːf/) in the sense of "a body of employees", the plural is always staff; otherwise, both staffs and staves (/steɪvz/) are acceptable, except in compounds, such as flagstaffs. Staves is rare in North America except in the sense of "magic rod", or the musical notation tool; stave of a barrel or cask is a back-formation from staves, which is its plural. (See the Plural to singular by back-formation section below.)
5. "Ducks" is also correct; http://oxforddictionaries.com/definition/english/duck
6. Referring to individual songs in the blues musical style: "play me a blues"; "he sang three blues and a calypso"
7. "Cannons" is more common in North America and Australia, while "cannon" as plural is more common in the United Kingdom.
8. Referring, in the plural, to animals in a herd: "fifty head of cattle"
9. As a unit of weight equal to 14 pounds

Certain names of peoples are not inflected for the plural:

Chinese (and others in -ese)

Swiss

Québécois (the feminine plural Québécoises is rarely borrowed into English)

This includes most names for Native American peoples, for example:

Cherokee

Cree

Comanche

Delaware

Hopi

Iroquois

Kiowa

Navajo

Ojibwa

Sioux

Zuni

Some exceptions include Algonquins, Apaches, Aztecs, Black Hawks, Chippewas, Hurons, Incas, Mayans, Mohawks, Oneidas, and Seminoles.

Note that English sometimes distinguishes between regular plural forms of demonyms/ethnonyms (e.g. "five Dutchmen", "several Irishmen"), and uncountable plurals used to refer to entire nationalities collectively (e.g. "the Dutch", "the Irish").

Certain other words borrowed from foreign languages such as Japanese and Māori are not inflected in the plural; see Irregular plurals from other languages below.

Plurals in -(e)n

The plural of a few nouns can also be formed from the singular by adding -n or -en, stemming from the Old English weak declension. Only the following three are commonly found:

ox	oxen	(particularly when referring to a team of draft animals, sometimes oxes in nonstandard American English)
child	children	(only possible plural; originated as a double plural, with -en added to Old English plural cildra/cildru, which also led to the archaic plural childer as in Childermas, occasionally still encountered in Ireland).
brother	brethren	(archaic as plural of brother meaning a male sibling, but often seen as plural of brother meaning a member of a religious congregation or fraternal organization;[references 8] originated as a double plural, with -en added to Early Middle English brether)

The following -(e)n plurals are found in dialectal, rare, or archaic usage:

bee	been	(dialectal, Ireland)
cow	kine	(archaic/regional; actually earlier plural "kye" [cf. Scots "kye" - "cows"] plus -en suffix, forming a double plural)
eye	eyen	(rare, found in some regional dialects, used by Shakespeare)
shoe	shoon	(rare/dialectal)
house	housen	(rare/dialectal, used by Rudyard Kipling in Puck of Pook's Hill)
hose	hosen	(rare/archaic, used in King James Version of the Bible)
knee	kneen	(archaic/obsolete)
tree	treen	(archaic/obsolete, used by William Browne)
aurochs	aurochsen	(alternative plural, also aurochs)

The word box, referring to a computer, may be pluralized semi-humorously to boxen in the hacker subculture. In the same context, multiple VAX computers are sometimes called Vaxen particularly if operating as a cluster, but multiple Unix systems are usually Unices along the Latin model.^{[references 9]}

Apophonic plurals

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

foot	feet
goose	geese
louse	lice
dormouse	dormice
man	men
mouse	mice (computer mouse can also take the regular plural form mouses)
tooth	teeth
woman	women /ˈwɪmᵻn/

This group consists of words that historically belong to the Old English consonant declension, see Germanic umlaut: I-mutation in Old English. There are many compounds of man and woman that form their plurals in the same way: postmen, policewomen, etc.

The plural of mongoose is mongooses. Mongeese is a back-formation by mistaken analogy to goose / geese and is often used in a jocular context. The form meese is sometimes also used humorously as the plural of moose — normally moose or mooses — or even of mouse.

Miscellaneous irregular plurals

Some words have irregular plurals that do not fit any of the types given here.

person – people (also persons, in more formal contexts; people can also be a singular noun with plural peoples.)

die – dice (in the context of gaming, where dice is also often used as the singular; and also in the semiconductor industry. Otherwise dies is used.)

penny – pence (in the context of an amount of money in Britain). The 1p or 1-cent coins are called pennies. Pence is abbreviated p (also in speech, as "pee"). For 10 pences see Headless nouns below.

Irregular plurals from Latin and Greek

English has borrowed a great many words from Classical Latin and Classical Greek. The general trend with loanwords is toward what is called Anglicization or naturalization, that is, the re-formation of the word and its inflections as normal English words. Many nouns (particularly ones from Latin) have retained their original plurals for some time after they are introduced. Other nouns have become Anglicized, taking on the normal "s" ending. In some cases, both forms are still competing.

The choice of a form can often depend on context: for a linguist, the plural of appendix is appendices (following the original language); for some physicians, the plural of appendix is appendixes. Likewise, a radio or radar engineer works with antennas, but an entomologist deals with antennae. The choice of form can also depend on the level of discourse: traditional Latin plurals are found more often in academic and scientific contexts, whereas in daily speech the Anglicized forms are more common. In the following table, the Latin plurals are listed, together with the Anglicized forms when these are more common.

Different paradigms of Latin pronunciation can lead to confusion as to the number or gender of the noun in question. As traditionally used in English, including scientific, medical, and legal contexts, Latin nouns retain the classical inflection with regard to spelling; however the pronunciation of those inflections is anglicized. The entomologist pronounced antennae as /ænˈtɛni/. This may cause confusion for those who have learned a different model of Latin pronunciation. The word alumnus/a is notorious in this regard, as a given inflection according to the traditional Anglicized model of Latin pronunciation sounds the same as a different number or gender in the more authentic model of pronunciation.

The fact that many of these plurals do not end in -s has led some of them to be reinterpreted as singular forms. This is particularly the case with the words datum and medium (as in a "medium of communication"), where the original plurals data and media are now, in many contexts, used more commonly as singular mass nouns: "The media is biased"; "This data shows us that ..." (although a number of scientists, especially of British origin, still say "These data show us that ..."). See below for more information. A similar process is causing words such as criteria and phenomena to be used as singular by some speakers, although this is still considered incorrect in standard usage (see below).

• Final a becomes -ae (also -æ), or just adds -s:

alumna	alumnae
formula	formulae/formulas
encyclopaedia (or encyclopædia) / encyclopedia	encyclopaedias / encyclopedias (encyclopaediae and encyclopediae are rare)

Scientific abbreviations for words of Latin origin ending in -a, such as SN for supernova, can form a plural by adding -e, as SNe for supernovae.

• Final ex or ix becomes -ices (pronounced /ᵻsiːz/), or just adds -es:

index	indices	/ˈɪndᵻsiːz/	or indexes
matrix	matrices	/ˈmeɪtrᵻsiːz/
vertex	vertices	/ˈvɜːrtᵻsiːz/

Some people treat process as if it belonged to this class, pronouncing processes /ˈprɒsᵻsiːz/ instead of standard /ˈprɒsɛsᵻz/. Since the word comes from Latin processus, whose plural in the fourth declension is processūs with a long u, this pronunciation is by analogy, not etymology.

• Final is becomes es (pronounced /iːz/):

axis	axes	/ˈæksiːz/
genesis	geneses	/dʒɛn.ə.siːz/
nemesis	nemeses	/ˈnɛməsiːz/
crisis	crises	/ˈkraɪsiːz/
testis	testes	/ˈtɛstiːz/

Axes (/ˈæksiːz/), the plural of axis, is pronounced differently from axes (/ˈæksᵻz/), the plural of ax(e).

• Final ies remains unchanged:

series	series
species	species

Specie for a singular of species is considered nonstandard. It is standard meaning the form of money, where it derives from the Latin singular ablative in the phrase in specie.

• Final um becomes -a, or just adds -s:

addendum	addenda
agendum (obsolete, not listed in most dictionaries)	agenda means a "list of items of business at a meeting" and has the plural agendas
corrigendum	corrigenda
datum	data (Now usually treated as a singular mass noun in both informal and educated usage, but usage in scientific publications shows a strong American/British divide. American usage generally prefers to treat data as a singular in all contexts, including in serious and academic publishing.[references 10][references 11][references 12] British usage now widely accepts treating data as singular in standard English,[references 13] including educated everyday usage[references 14] at least in non-scientific use.[references 15] British scientific publishing usually still prefers treating data as a plural.[references 16] Some British university style guides recommend using data for both the singular and the plural use[references 17] and some recommend treating it only as a singular in connection with computers.[references 18]) In engineering, drafting, surveying, and geodesy, and in weight and balance calculations for aircraft, a datum (plural datums or data) is a reference point, surface, or axis on an object or the Earth's surface against which measurements are made.
forum	fora/forums
medium	media (in communication systems and digital computers. This is now often treated as a singular mass noun)/ mediums (spiritualists, or items of medium size)
memorandum	memoranda/memorandums
millennium	millennia
ovum	ova
referendum	referendums is often taken to mean plebiscites, and referenda as the propositions voted on
spectrum	spectra (as in power spectrum in electrical engineering)

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

alumnus	alumni
corpus	corpora
census	censuses
focus	foci
genus	genera
prospectus	prospectuses (plural prospectus is rare although technically correct)
radius	radii
campus	Campuses (The Latinate plural form campi is sometimes used, particularly with respect to colleges or universities; however, it is sometimes frowned upon. By contrast, the common plural form campuses is universally accepted.)
succubus	succubi
stylus	styli
syllabus	syllabi/syllabuses (in fact the Latin plural is syllabūs)
viscus	viscera
virus	viruses ( see Plural form of words ending in -us#Virus )

cactus	cactuses/cacti (in Arizona many people avoid either choice with cactus as both singular and plural.)
fungus	fungi
hippopotamus	hippopotamuses/hippopotami
octopus	octopuses (note: octopi also occurs, although it is strictly speaking unfounded,[references 19] because it is not a Latin noun of the second declension, but rather a Latinized form of Greek ὀκτώ-πους, eight-foot. The theoretically correct form octopodes is rarely used.)
platypus	platypuses (same as octopus: platypi occurs but is etymologically incorrect, and platypodes, while technically correct, is even rarer than octopodes)
terminus	termini/terminuses
uterus	uteri/uteruses

• Final us remains unchanged in the plural (fourth declension - the plural has a long ū to differentiate it from the singular short ǔ):

meatus	meatus (or meatuses)
status	status (but usually statuses)

Colloquial usages based in a humorous fashion on the second declension include Elvii to refer to multiple Elvis impersonators and Loti, used by petrolheads to refer to Lotus automobiles in the plural.

Some Greek plurals are preserved in English (cf. Plurals of words of Greek origin):

• Final on becomes -a:

automaton	automata
criterion	criteria
phenomenon	phenomena
polyhedron	polyhedra

• Final as in one case changes to -antes:

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

• Final ma in nouns of Greek origin can become -mata, although -s is usually also acceptable, and in many cases more common.

stigma	stigmata/stigmas
stoma	stomata/stomas
schema	schemata/schemas
dogma	dogmata/dogmas
lemma	lemmata/lemmas
anathema	anathemata/anathemas

Irregular plurals from other languages

• Some nouns of French origin add an -x, which may be silent or pronounced /z/:

beau	beaux or beaus
bureau	bureaux or bureaus
château	châteaux or châteaus
tableau	tableaux or tableaus

See also French compounds below.

Foreign terms may take native plural forms, especially when the user is addressing an audience familiar with the language. In such cases, the conventionally formed English plural may sound awkward or be confusing.

• Nouns of Slavic origin add -a or -i according to native rules, or just -s:

kniazhestvo	kniazhestva/kniazhestvos
kobzar	kobzari/kobzars
oblast	oblasti/oblasts

• Nouns of Hebrew origin add -im or -ot (generally m/f) according to native rules, or just -s:

cherub	cherubim/cherubs
seraph	seraphim/seraphs
matzah	matzot/matzahs
kibbutz	kibbutzim/kibbutzes

Ot is pronounced os (with unvoiced s) in the Ashkenazi dialect.

• Many nouns of Japanese origin have no plural form and do not change:

benshi	benshi
otaku	otaku
samurai	samurai

Other nouns such as kimonos, ninjas, futons, and tsunamis are more often seen with a regular English plural.

• In New Zealand English, nouns of Māori origin can either take an -s or have no separate plural form. Words more connected to Māori culture and used in that context tend to retain the same form, while names of flora and fauna may or may not take an -s, depending on context. Many regard omission as more correct:

kiwi[b 1]	kiwi/kiwis
kowhai	kowhai/kowhais
Māori[b 2]	Māori/(occasionally Māoris)
marae	marae
tui	tuis/tui
waka	waka

Notes:

1. When referring to the bird, kiwi may or may not take an -s; when used as an informal term for a New Zealander, it always takes an -s.
2. Māori, when referring to a person of that ethnicity, does not usually take an -s. Many speakers avoid the use of Māori as a noun, and instead use it only as an adjective.

• Some words borrowed from Inuktitut (spoken in Canada and Alaska) retain the original plurals:

Inuk	Inuit
inukshuk	inukshuit
Iqalummiuq	Iqalummiut ("inhabitant of Iqaluit")
Nunavimmiuq	Nunavimmiut ("inhabitant of Nunavik")
Nunavummiuq	Nunavummiut ("inhabitant of Nunavut")

• Nouns from languages other than the above generally form plurals as if they were native English words:

canoe	canoes
cwm	cwms (Welsh valley)
igloo	igloos
kangaroo	kangaroos
kayak	kayaks
kindergarten	kindergartens (in the original German, the plural form would be Kindergärten)
pizza	pizzas
sauna	saunas
ninja	ninjas

Plurals of compound nouns

The majority of English compound nouns have one basic term, or head, with which they end. These are nouns and are pluralized in typical fashion:

able seaman	able seamen
head banger	head bangers
yellow-dog contract	yellow-dog contracts

Some compounds have one head with which they begin. These heads are also nouns and the head usually pluralizes, leaving the second, usually a post-positive adjective, term unchanged:

attorney general	attorneys general
bill of attainder	bills of attainder
court martial	courts martial
director general	directors general
fee simple absolute	fees simple absolute
governor-general	governors-general
passerby	passersby
ship of the line	ships of the line
son-in-law	sons-in-law
minister-president	ministers-president
chief of staff	chiefs of staff
procurator fiscal (in Scotland)	procurators fiscal

It is common in informal speech to instead pluralize the last word in the manner typical of most English nouns, but in edited prose, the forms given above are preferred.

If a compound can be thought to have two heads, both of them tend to be pluralized when the first head has an irregular plural form:

man-child	men-children
manservant	menservants
woman doctor	women doctors (no longer in common use)

Two-headed compounds in which the first head has a standard plural form, however, tend to pluralize only the final head:

city-state	city-states
nurse-practitioner	nurse-practitioners
scholar-poet	scholar-poets

In military usage, the term general, as part of an officer's title, is etymologically an adjective, but it has been adopted as a noun and thus a head, so compound titles employing it are pluralized at the end:

brigadier general	brigadier generals
major general	major generals

For compounds of three or more words that have a head (or a term functioning as a head) with an irregular plural form, only that term is pluralized:

man-about-town	men-about-town
man-of-war	men-of-war
woman of the street	women of the street

For many other compounds of three or more words with a head at the front —especially in cases where the compound is ad hoc or the head is metaphorical— it is generally regarded as acceptable to pluralize either the first major term or the last (if open when singular, such compounds tend to take hyphens when plural in the latter case):

ham on rye	hams on rye/ham-on-ryes
jack-in-the-box	jacks-in-the-box/jack-in-the-boxes
jack-in-the-pulpit	jacks-in-the-pulpit/jack-in-the-pulpits

With a few extended compounds, both terms may be pluralized—again, with an alternative (which may be more prevalent, e.g., heads of state):

head of state	heads of states/heads of state
son of a bitch	sons of bitches/sons-of-a-bitch

With extended compounds constructed around o, only the last term is pluralized (or left unchanged if it is already plural):

cat-o'-nine-tails	cat-o'-nine-tails
jack-o'-lantern	jack-o'-lanterns
will-o'-the-wisp	will-o'-the-wisps

See also the Headless nouns section below.

French compounds

Many English compounds have been borrowed directly from French, and these generally follow a somewhat different set of rules. French-loaned compounds with a head at the beginning tend to pluralize both words, according to French practice:

agent provocateur	agents provocateurs
entente cordiale	ententes cordiales
fait accompli	faits accomplis
idée fixe	idées fixes

For compounds adopted directly from French where the head comes at the end, it is generally regarded as acceptable either to pluralize both words or only the last:

beau geste	beaux gestes/beau gestes
belle époque	belles époques/belle époques
bon mot	bons mots/bon mots
bon vivant	bons vivants/bon vivants
bel[c 1] homme	beaux hommes

Notes:

1. If the adjectives beau "beautiful/handsome", nouveau "new", or vieux "old" precede a masculine singular noun beginning with a vowel or a mute "h", they are changed to bel, nouvel, and vieil to help ease the pronunciation. The normal plural rule applies to plural nouns.

French-loaned compounds longer than two words tend to follow the rules of the original language, which usually involves pluralizing only the head at the beginning:

aide-de-camp	aides-de-camp
cri du coeur	cris du coeur
coup d'état	coups d'état
tour de force	tours de force

but:

tête-à-tête

tête-à-têtes

A distinctive case is the compound film noir. For this French-loaned artistic term, English-language texts variously use as the plural films noirs, films noir, and, most prevalently, film noirs. The 11th edition of the standard Merriam-Webster's Collegiate Dictionary (2006) lists film noirs as the preferred style. Three primary bases may be identified for this:

1. Unlike other compounds borrowed directly from French, film noir is used to refer primarily to English-language cultural artifacts; a typically English-style plural is thus unusually appropriate.
2. Again, unlike other foreign-loaned compounds, film noir refers specifically to the products of popular culture; consequently, popular usage holds more orthographical authority than is usual.
3. English has adopted noir as a stand-alone noun in artistic contexts, leading it to serve as the lone head in a variety of compounds (e.g., psycho-noir, sci-fi noir).

Plurals of letters and abbreviations

The plural of individual letters is normally written with -'s: there are two h's in this sentence; mind your p's and q's; dot the i's and cross the t's.

Some people extend this use of the apostrophe to other cases, such as plurals of numbers written in figures (e.g. "1990's"), words used as terms (e.g. "his writing uses a lot of but's"). However others prefer to avoid this method (which can lead to confusion with the possessive -'s), and write 1990s, buts; this is the style recommended by the Chicago Manual of Style.

Likewise, acronyms and initialisms are normally pluralized simply by adding (lowercase) -s, as in MPs, although the apostrophe is sometimes seen. Use of the apostrophe is more common in those cases where the letters are followed by periods (B.A.'s), or where the last letter is S (as in PS's and CAS's, although PSs and CASs are also acceptable; the ending -es is also sometimes seen).

English (like Latin and certain other European languages) can form a plural of certain one-letter abbreviations by doubling the letter: p. ("page"), pp. ("pages"). Other examples include ll. ("lines"), ff. ("following lines/pages"), hh. ("hands", as a measure), PP. ("Popes"), ss. (or §§) ("sections"), vv. ("volumes"). Some multi-letter abbreviations can be treated the same way, by doubling the final letter: MS ("manuscript"), MSS ("manuscripts"); op. ("opus"), opp. ("opera" as plural of opus).

However, often the abbreviation used for the singular is used also as the abbreviation for the plural; this is normal for most units of measurement and currency. The SI unit symbols are officially not considered abbreviations and not pluralized, as in 10 m ("10 metres").

Headless nouns

In The Language Instinct, linguist Steven Pinker discusses what he calls "headless words", typically bahuvrihi compounds, like lowlife and flatfoot, in which life and foot are not heads semantically; that is, a lowlife is not a type of life, and a flatfoot is not a type of foot. When the common form of such a word is singular, it is treated as if it has a regular plural, even if the final constituent of the word is usually pluralized in a nonregular fashion. Thus the plural of lowlife is lowlifes, not "lowlives", according to Pinker. Other proposed examples include:

sabertooth	sabertooths
still life	still lifes
tenderfoot	tenderfoots

An exception is Blackfoot, of which the plural can be Blackfeet, though that form of the name is officially rejected by the Blackfoot First Nations of Canada.

Another analogous case is that of sport team names such as the Florida Marlins and Toronto Maple Leafs. For these, see Teams and their members below.

Defective nouns

Plurals without singulars

Some nouns have no singular form. Such a noun is called a plurale tantum. Examples include cattle, thanks, clothes (originally a plural of cloth).

A particular set of nouns, describing things having two parts, comprises the major group of pluralia tantum in modern English:

glasses (a pair of spectacles), pants, panties, pantyhose, pliers, scissors, shorts, suspenders, tongs (metalworking & cooking), trousers, etc.

These words are interchangeable with a pair of scissors, a pair of trousers, and so forth. In the American fashion industry it is common to refer to a single pair of pants as a pant —though this is a back-formation, the English word (deriving from the French pantalon) was originally singular. In the same field, one half of a pair of scissors separated from the other half is, rather illogically, referred to as a half-scissor. Tweezers used to be part of this group, but tweezer has come into common usage only since the second half of the twentieth century.

There are also some plural nouns whose singular forms exist, though they are much more rarely encountered than the plurals:

nuptial	nuptials
phalanx[d 1]	phalanges
tiding	tidings
victual	victuals
viscus	viscera

Notes:

1. In medical terminology, a phalanx is any bone of the finger or toe. A military phalanx is pluralized phalanxes.

Singulars without plurals

Mass nouns (or uncountable nouns) do not represent distinct objects, so the singular and plural semantics do not apply in the same way. Some examples:

• Abstract nouns

deceit, information, cunning, and nouns derived from adjectives, such as honesty, wisdom, beauty, intelligence, poverty, stupidity, curiosity, and words ending with "ness", such as goodness, freshness, laziness, and nouns which are homonyms of adjectives with a similar meaning, such as good, bad (can also use goodness and badness), hot, and cold.

• In the arts and sciences

chemistry, geometry, surgery, the blues,^{[e 1]} jazz, rock and roll, impressionism, surrealism. This includes those that look plural but function as grammatically singular in English: mathematics (and in British English the shortened form 'maths'), physics, mechanics, dynamics, statics, thermodynamics, aerodynamics, electronics, hydrodynamics, robotics, acoustics, optics, computer graphics, cryptography, ethics, linguistics, etc.; e.g., Mathematics is fun; Cryptography is the science of codes and ciphers; theromodynamics is the science of heat. Data often functions as a singular in terms such as 'data collection' or 'data processing'.

• Chemical elements and other physical entities:

aluminum (US) / aluminium (UK), copper, gold, oxygen, nitrogen, carbon, equipment, furniture, traffic, air and water

Notes:

1. Referring to the musical style as a whole.

Some mass nouns can be pluralized, but the meaning in this case may change somewhat. For example, when I have two grains of sand, I do not have two sands; I have sand. There is less sand in your pile than in mine, not fewer sands. However, there could be the 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 The Sands of Mars.

It is rare to pluralize furniture in this way and information is never pluralized.

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, don't run with scissors, defer to those with greater knowledge), deceits as a series of instances of deceitful behavior (lied on income tax, dated my wife), 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").

The pair specie and species both come from a Latin word meaning "kind", but they do not form a singular-plural pair. In Latin, specie is the ablative singular form, while species is the nominative form, which happens to be the same in both singular and plural. In English, species behaves similarly —as a noun with identical singular and plural— while specie is treated as a mass noun, referring to money in the form of coins (the idea is of "[payment] in kind").^{[references 20]}

Singulars as plural and plurals as singular

Plural words becoming singular

Plural in form but singular in construction

Certain words which were originally plural in form have come to be used almost exclusively as singulars (usually uncountable); for example billiards, measles, news, mathematics, physics etc. Some of these words, such as news, are strongly and consistently felt as singular by fluent speakers. These words are usually marked in dictionaries with the phrase "plural in form but singular in construction" (or similar wording). Others, such as aesthetics, are less strongly or consistently felt as singular; for the latter type, the dictionary phrase "plural in form but singular or plural in construction" recognizes variable usage.

Plural form became a singular form

Some words of foreign origin are much better known in their (foreign-morphology) plural form, and are often not even recognized by English speakers as having plural form; descriptively, in English morphology many of these simply are not in plural form, because English has naturalized the foreign plural as the English singular. Usage of the original singular may be considered pedantic, hypercorrective, or incorrect^{[references 21]} by some speakers. In the examples below, the original plural is now commonly used as a singular, and in some cases a regular English plural (effectively a double plural) has been formed from it.

Original singular	Original plural/ common singular	Common plural
agendum	agenda[f 1]	agendas
alga	algae	algae
biscotto	biscotti	biscotti
candelabrum	candelabra	candelabras
datum[f 2]	data	data (mass noun)
graffito	graffiti	graffiti (mass noun)
insigne	insignia	insignias
panino	panini	paninis (currently gaining use)
paparazzo	paparazzi	paparazzi
spaghetto	spaghetti	spaghetti (mass noun)

Magazine was derived from Arabic via French. It was originally plural, but in French and English, it is always regarded as singular.

Some other words whose plurals are sometimes misused as singulars include:

criterion	criteria
phenomenon	phenomena

Notes:

1. An agenda commonly is used to mean a list of agenda.
2. A single piece of data is sometimes referred to as a data point. In engineering, drafting, surveying, and geodesy, and in weight and balance calculations for aircraft, a datum (plural datums or data) is a reference point, surface, or axis on an object or the earth’s surface against which measurements are made.

Back-formation

Some words have unusually formed singulars and plurals, but develop "normal" singular-plural pairs by back-formation. For example, pease (modern peas) was in origin a singular with plural peasen. However, pease came to be analysed as plural by analogy, from which a new singular pea was formed; the spelling of pease was also altered accordingly, surviving only in the name of the dish pease porridge or pease pudding. Similarly, termites was the three-syllable plural of termes; this singular was lost, however, and the plural form reduced to two syllables. Syringe is a back-formation from syringes, itself the plural of syrinx, a musical instrument. Cherry is from Norman French cherise. Phases was once the plural of phasis, but the singular is now phase. The nonstandard, offensive, and now obsolete Chinee and Portugee singulars are back-formations from the standard Chinese and Portuguese.

Kudos is a singular Greek word meaning praise, but is often taken to be a plural. At present, however, kudo is considered an error, though the usage is becoming more common as kudos becomes better known. The name of the Greek sandwich style gyros is increasingly undergoing a similar transformation.

The term, from Latin, for the main upper arm flexor in the singular is the biceps muscle (from biceps brachii); however, many English speakers take it to be a plural and refer to the muscle of only one arm, by back-formation, as a bicep. The correct —although very seldom used— Latin plural would be bicipites.

The word sastrugi (hard ridges on deep snow) is of Russian origin and its singular is sastruga; but the imaginary Latin-type singular sastrugus has sometimes been used.

Geographical plurals used as singular

Geographical names may be treated as singular even if they are plural in form, if they are regarded as representing a single entity such as a country: The United States is a country in North America (similarly with the Netherlands, the Philippines, Trinidad and Tobago, etc.). However, if the sense is a group of geographical objects, such as islands or mountains, a plural-form name will be treated as plural: The Hebrides are a group of islands off the coast of Scotland.

Singulars with collective meaning treated as plural

A number of words like army, company, crowd, family, fleet, government, majority, mess, number, pack, party and team may refer either to a single entity or the members of the set composing it. If the latter meaning is intended, the word (though singular in form) may be treated as if it were a plural, in that it may take a plural verb and be replaced with a plural pronoun: the government are considering their position (alternatively the government is considering its position). See synesis.

Thus, as H. W. Fowler describes, in British English they are "treated as singular or plural at discretion"; Fowler notes that occasionally a "delicate distinction" is made possible by discretionary plurals: "The Cabinet is divided is better, because in the order of thought a whole must precede division; and The Cabinet are agreed is better, because it takes two or more to agree."^{[references 22]}

Plurals of numbers

The following rules apply to the plurals of numerical terms such as dozen, score, hundred, thousand, million, and similar:

• When modified by a number, the plural is not inflected, that is, has no -s added. Hence one hundred, two million, four score, etc. (The resulting quantitative expressions are treated as numbers, in that they can modify nouns directly: three dozen eggs, although of is used before pronouns or definite noun phrases: three dozen of them/of those eggs.)
• When not modified by a number, the plural takes -s as usual, and the resulting expression is not a number (it requires of if modifying a noun): I have hundreds, dozens of complaints, the thousands of people affected.
• When the modifier is a vaguer expression of number, either pattern may be followed: several hundred (people) or several hundreds (of people).
• When the word has a specific meaning rather than being a simple expression of quantity, it is pluralized as an ordinary noun: Last season he scored eight hundreds [=scores of at least 100 runs]. The same applies to other numbers: My phone number consists of three fives and four sixes.
• Note the expressions by the dozen etc. (singular); in threes [=in groups of three] etc. (plural); eight sevens are fifty-six etc.

Nouns used attributively

Nouns used attributively to qualify other nouns are generally in the singular, even though for example, a dog catcher catches more than one dog, and a department store has more than one department. This is true even for some binary nouns where the singular form is not found in isolation, such as a trouser mangle or the scissor kick. This is also true where the attribute noun is itself qualified with a number, such as a twenty-dollar bill, a ten-foot pole or a two-man tent. The plural is used for pluralia tantum nouns: a glasses case is for eyeglasses, while a glass case is made of glass (but compare eyeglass case); also an arms race versus arm wrestling. The plural may be used to emphasise the plurality of the attribute, especially in British English but very rarely in American English: a careers advisor, a languages expert. The plural is also more common with irregular plurals for various attributions: women killers are women who kill, whereas woman killers are those who kill women.

Teams and their members

In the names of sports teams, sometimes a noun will be given a regular plural in -s even though that noun in normal use has an irregular plural form (a particular case of headless nouns as described above). For example, there are teams called the Florida Marlins and the Toronto Maple Leafs, even though the word marlin normally has its plural identical to the singular, and the plural of leaf is leaves. (This does not always apply; for example, there is the Minnesota Lynx, not *Lynxes.) Some teams use a non-standard plural spelling in their names, such as the Boston Red Sox and Chicago White Sox.

When a sport team's name is plural, the corresponding singular is often used to denote a member of that team; for example a player for the Cincinnati Reds may be referred to as a (Cincinnati) Red. This also applies to the St. Louis Blues ice hockey team, even though it is named after the song the "St. Louis Blues", and thus blues was originally a singular identical to its plural.

When a team's name is plural in form but cannot be singularized by removing an -s, as in Boston Red Sox, the plural is sometimes used as a singular (a player may be referred to as "a Red Sox"). Oftentimes, the singular "Red Sox" will be pronounced as if it were "Red Sock," even though the spelling suggests otherwise.

When a team's name is singular, as in Miami Heat and Colorado Avalanche, the same singular word may also sometimes be used to denote a player (a Heat, an Avalanche). When referring to more than one player, it is normal to use Heat players or Avalanche players (although in the latter case the team's plural-form nickname Avs is also available).

For the (especially British) treatment of teams as plural even if they have singular names, see Singulars with collective meaning treated as plural above.

Adjectives as collective plurals

Certain adjectives can be used, uninflected, as plurals denoting people of the designated type. For example, unemployed and homeless can be used to mean "unemployed people" and "homeless people", as in There are two million unemployed. Such usage is common with the definite article, to denote people of a certain type generally: the unemployed, the homeless.

This is common with certain nationalities: the British, the Dutch, the English, the French, the Irish, the Spanish, the Welsh, and those where the adjective and noun singular and plural are identical anyway, including the Swiss and those in -ese (the Chinese etc.). In the case of most nationalities, however, the plural of the demonym noun is used for this purpose: (the) Americans, (the) Poles. Cases where the adjective formation is possible, but the noun provides a commonly used alternative, include the Scottish (or more commonly (the) Scots), the Danish (or (the) Danes), the Finnish (or (the) Finns), the Swedish (or (the) Swedes).

The noun is normally used anyway when referring to specific sets of people (five Frenchmen, a few Spaniards), although the adjective may be used especially in case of a group of mixed or unspecified sex, if the demonym nouns are gender-specific: there were five French (or French people) in the bar (if neither Frenchmen or Frenchwomen would be appropriate).

See also

• English verbs
• English personal pronouns
• Count noun
• Mass noun
• Singular they

References

1. English Irregular Plural Nouns
2. UNIT S4: YS OR IES?
3. Book titles include Mary Fulbrook, The Two Germanies. 1945-1990 (Basingstoke: Macmillan, 1996); Henry Ashby Turner, The two Germanies since 1945 (New Haven: Yale UP, 1987).
4. Entry for "money" in dictionary.com
5. Emerson, Oliver Farrar (1921). The history of the English language. Macmillan. p. 299. OCLC 317104.
6. E.g. Collins English Dictionary, 6th ed. (Glasgow: HarperCollins, 2003).
7. Partridge, Eric, Usage and Abusage: A Guide to Good English, revised by Janet Whitcut (New York and London: W. W. Norton, 1997), pp. 238–39.
8. Dictionary.com entry for "brother".
9. Raymond, Eric (1993). "How Jargon Works". The New Hacker's Dictionary. p. 12. But note that 'Unixen' and 'Twenexen' are never used. It has been suggested that this is because '-ix' and '-ex' are Latin singular endings that attract a Latinate plural.
10. "Sometimes scientists think of data as plural, as in These data do not support the conclusions. But more often scientists and researchers think of data as a singular mass entity like information, and most people now follow this in general usage." http://www.bartleby.com/61/51/D0035100.html
11. "...of the 136 distinguished consultants on usage polled for the 1975 Harper Dictionary of Contemporary Usage, 49% responded that they use "The data is..." in writing. Also, in casual speech, 65% use data as singular. Those who defend "The data is..." often point to the fact that agenda is also, strictly, a plural, but is nearly always regarded as a single list and takes a singular verb. You'll probably never hear anyone ask: "Are the agenda interesting?" http://www.gi.alaska.edu/ScienceForum/ASF3/334.html
12. Summary of dictionary sources and scholarly usage
13. New Oxford Dictionary of English, 1999
14. "...in educated everyday usage as represented by the Guardian newspaper, it is nowadays most often used as a singular." http://www.eisu2.bham.ac.uk/johnstf/revis006.htm
15. AskOxford: data
16. http://www.eisu2.bham.ac.uk/johnstf/revis006.htm
17. UoN Style Book - Singular or plural - Media and Public Relations Office - The University of Nottingham
18. http://openlearn.open.ac.uk/mod/resource/view.php?id=182902
19. AskOxford: What are the plurals of 'octopus', 'hippopotamus', 'syllabus'?
20. Harper, Douglas. "Specie". Online Etymological Dictionary. Retrieved 29 August 2010.
21. "The word agenda, for example, was originally plural (from agendum: 'something to be acted on') but is nowadays used only as a singular, and nobody in their right mind would insist that it should be used as a plural." http://www.eisu2.bham.ac.uk/johnstf/revis006.htm
22. Fowler, H. W., A Dictionary of Modern English Usage, 2nd ed., revised by Sir Ernest Gowers (New York and Oxford: Oxford University Press, 1965), 403.

External links

• Rules for Irregular Plural Formation of Nouns summary by Pat Byrd, Department of Applied Linguistics & ESL, Georgia State University
• An Algorithmic Approach to English Pluralization by Damian Conway
• Freebase Pluraliser API plural names of freebase.com topics by David Huynl