Is the word are singular or plural

Singular and Plural Nouns

Nouns are the words used as the names of persons, animals, places, things, ideas or events.

There are two types of nouns in English Grammar. One refers to the singular noun and the other refers to the plural noun.  

These two nouns are also otherwise called the singular number and the plural number. 

Singular Noun Definition:

When a noun refers to one person or thing, it is said to be in the Singular Noun/Number. 

Singular Noun Examples: 

These Singular Nouns can be categorised in the following manner.

• Singular Nouns related to one person:

singer, dancer, artist, photographer, magician, driver, officer, doctor, engineer, principal, peon, labor, nurse, shopkeeper, gatekeeper, sweeper, salesman, philosopher, teacher, minister, president, businessperson, writer, student, friend, boy, girl, toddler, baby, teenager, woman, man, person etc.,

• Singular Nouns related to one place: 

bank, airport, continent, country, state, city, town, village, hotel, school, classroom, university, college, park, shop, coffee shop, zoo, water park, mall, supermarket, post office, police station,  house, laboratory, library, museum, stadium, building, restaurant, temple, mosque, church, etc.,

• Singular Nouns related to one thing: 

ruler, chair, mobile, dictionary, carpet, lawnmower, bus, computer, courage, telephone, spade,  printer, hammer, bicycle, pen, table, ship, calculator, crayon, sofa, truck, television, pencil, fridge, book, lamp, ladder, train, cooker, whiteboard, marker, duster, register, map, globe etc.,

Plural Noun Definition:

When a noun refers to more than one person or thing, it is said to be in the Plural Noun/Number.

Plural Noun Examples:

rooms, tables,  computers, pieces of chalk, students, teachers, parents, books, pens, stories etc.,

Forming of Plural Noun:

There are various RULES to form plural nouns from singular. Most of the rules have been provided here. 

They are as follows:

Rule No 1: Most of the Nouns in English form their plural noun by adding ‘s’ at the end of a singular noun. 

Examples:

• actor – actors
• animal – animals
• answer – answers
• boat – boats
• book – books
• bottle –  bottles
• car – cars
• cat –  cats
• cap – caps
• cow – cows
• day – days
• desk – desks
• dog – dogs
• example – examples
• fact- facts 
• goat – goats
• group – groups
• girl -girls
• house – houses
• lake – lakes
• pencil – pencils
• pen – pens
• school – schools
• snake – snakes
• system – systems
• teacher – teachers
• thing – things

Rule No 2: When Nouns end in  –’o’,  we generally add –’es’ to form plurals:

Examples:

• buffalo – buffaloes
• cargo – cargoes
• echo – echoes
• hero – heroes
• mango – mangoes
• mosquito – mosquitoes
• negro – negroes
• potato – potatoes
• tomato – tomatoes
• torpedo – torpedoes
• veto – vetoes
• volcano – volcanoes
• zero – zeroes

Exception 1:  Though some nouns end in –’o’, we add only ‘s’.

• canto – cantos
• commando – commandos
• Eskimo – Eskimos
• logo – logos
• memento – mementos
• memo – memos
• photo – photos
• piano – pianos
• pro – pros
• solo – solos

Exception 2: But for some nouns, we can add  ‘s’ and ‘es’.  Both are correct.

• buffalo – buffalos/buffaloes
• cargo – cargos/cargoes
• commando – commandos/commandoes
• memento – mementos/mementoes
• mosquito – mosquitos/mosquitoes
• portico – porticos/porticoes
• volcano – volcanos/volcanoes

Rule No 3: When a noun ends in –’o’ but preceded by a vowel, we add only “s”.

Examples:

• bamboo – bamboos
• cuckoo – cuckoos
• cameo – cameos
• folio – folios
• kangaroo – kangaroos
• portfolio – portfolios
• radio – radios
• studio – studios
• video – videos

Rule No 4: When Nouns end in -s, -sh, -ch (soft), or -x, we add -’es’ to form plurals:

Examples:

• access – accesses
• address – addresses
• atlas – atlases
• ax –  axes
• beach – beaches
• bench – benches
• box – boxes
• branch – branches
• brush – brushes
• bunch – bunches
• bus – buses
• church – churches
• class – classes
• congress – congresses
• crash – crashes
• dish – dishes
• dress – dresses
• fox – foxes
• gas – gases
• kiss – kisses
• lunch – lunches
• mass – masses
• match – matches
• patch – patches
• radish – radishes
• research – researches
• search – searches
• sketch – sketches
• speech – speeches
• stress – stresses
• status – statuses
• stitch – stitches
• success – successes
• tax – taxes
• touch: touches
• watch – watches
• wish – wishes
• witch – witches

Rule No 5: When Nouns end in –’y’ and –’y’ is preceded by a consonant, we change the ‘y’ into ‘i’ and add -’es’ to form plurals.

Examples:

• berry – berries
• cherry – cherries
• city – cities
• colony – colonies
• copy – copies
• country – countries
• daisy – daisies
• duty – duties
• dictionary – dictionaries
• enemy – enemies
• fairy – fairies
• family – families
• fly – flies
• gallery – galleries
• hobby – hobbies
• injury – injuries
• lady – ladies
• lorry – lorries
• lily – lilies
• party – parties
• penny – pennies
• pony – ponies
• puppy – puppies
• reply – replies
• story – stories
• study – studies
• theory – theories
• trophy – trophies
• university – universities
• victory – victories

Exception: But, in case –’y’ is preceded by a vowel, we add only –’s’. 

• boy – boys
• day – days
• delay – delays
• donkey – donkeys
• essay – essays
• guy – guys
• holiday – holidays
• joy – joys
• key – keys
• monkey – monkeys
• play – plays
• ray – rays
• storey – storeys
• toy – toys
• tray – trays
• valley – valleys

Rule No 6: When Nouns end in -’ch’ and ‘ch’ is pronounced as ‘k’, we add –’s’ to form the plural. 

Examples:

• hierarch – hierarchs
• epoch – epochs
• eunuch – eunuchs
• monarch – monarchs
• patriarch – patriarchs
• matriarch – matriarchs
• stomach – stomachs
• hierarch – hierarchs

Rule No 7: When Nouns end in ‘f’ or ‘fe’, we replace it with –‘v’ and then add -‘es’ to form the plural.

Examples:

• calf – calves
• elf – elves
• half –  halves
• hoof – hooves
• knife – knives
• leaf – leaves
• life – lives
• leaf – leaves
• loaf – loaves
• scarf – scarves
• self – selves
• sheaf – sheaves
• shelf – shelves
• thief – thieves
• wife – wives
• wolf – wolves

Exception 1:  The following nouns become plural when we add only ‘s’.

• belief – beliefs
• brief – briefs
• chief – chiefs
• cliff – cliffs
• cuff –  cuffs
• gulf – gulfs
• grief – griefs 
• proof – proofs
• roof – roofs
• safe – safes
• scarf – scarfs
• serf – serfs
• strife – strifes
• turf – turfs

Exception 2:  But for some nouns, we can add both -’s’ or –’ves’.  Both are correct.

• dwarf – dwarfs or dwarves 
• hoof – hoofs or hooves
• scarf – scarfs or scarves
• kerchief – kerchief or kerchieves
• wharf – wharfs or wharves 

Rule No 8: We change inside vowels of some nouns to make them plural

Examples:

• dormouse – dormice
• goose – geese
• foot – feet
• louse – lice
• man – men
• mouse – mice
• person – people
• tooth – teeth
• woman – women

Exception:  We add -’en’ to a few nouns to make them plural.

• child –  children
• ox – oxen
• brother – brethren (brothers also correct)
• cow – kine (cows also correct)
• sister – sistren (sisters also correct)

Rule No 9: Some nouns are the same in singular and plural.

Examples:

• aircraft – aircraft
• barracks –  barracks
• deer – deer
• dozen – dozen
• gross – gross
• pair -pair
• score – score
• series – series
• sheep – sheep
• spacecraft – spacecraft
• species – species

Rule No 10: Some nouns have two types of  plural forms

Examples:

• antelope – antelope or antelopes
• fish – fish or fishes
• reindeer – reindeer or reindeers
• herring – herring or herrings

Rule No 11: Some nouns are used only in the plural form

Names of certain tools and things:

bellows, scissors, spectacles, binoculars, glasses, goggles, sunglasses

headphones, pliers, tweezers, tongs,  pincers, chopsticks etc.

Names of clothes and footwear:

shorts, trousers, panties, briefs, drawers, tights, jeans, pants, pyjamas, clothes, shoes, sandals, gloves, slippers,  boots, socks etc.

Note: We can use ‘a pair of’ with these plural nouns. 

Examples: 

a pair of trousers, a pair of pants, a pair of glasses, a pair of scissors, a pair of chopsticks, a pair of sandals, a pair of gloves etc.,

Certain other different nouns:

earnings, belongings, assets, congratulations, thanks, annals, 

outskirts, premises, surroundings, environs, alms, riches, eaves etc.,

Certain Collective Nouns:

Poultry, cattle, vermin, people, gentry, children etc.,

Rule No 12: Some nouns are used only in the singular form

Names of subjects and others:

mathematics, physics, economics, electronics, news, innings, politics, wages, ethics etc.,

Names of some common diseases:

measles, mumps, rickets etc.,

Names of some games: 

billiards, draughts, carroms etc.,

Certain Collective Nouns:

knowledge, information, stationery, luggage, furniture, homework, scenery, bread, expenditure money, power etc.,

Some nouns that refer to number, weight etc., if preceded by numerals.

dozen, gross, hundred, thousand, horse-power, million-foot etc.,

Examples:

• Two dozen bananas
• Two gross of pencils
• Three hundred rupees
• A three-foot stick
• Four thousand dollars

Note: But, we add –’s’ to these nouns if they are used without numerals and are followed by ‘of’.

Examples:

• Dozens of bananas
• Hundreds of rupees
• Thousands of people
• The tree is 30 feet high.

Rule No 13: Change of Compound Nouns into plural:

Examples:

Compound Nouns in Singular	Compound Nouns in Plural
By adding -’s’  to the base or important word
Governor-general	Governors-general
Doctor Of Philosophy	Doctors Of Philosophy
Commander-in-chief	Commanders-in-chief
Brother-in-law	Brothers-in-law
Father-in-law	Fathers-in-law
Mother-in-law	Mothers-in-law
Sister-in-law	Sisters-in-law
Son-in-law	Sons-in-law
Passer-by	Passers-by
Looker-on	Lookers -on
Sergeant Major	Sergeants Major
Heir Apparent	Heirs Apparent
By removing -’y’ and adding -’ies’  to the base or important word
Attorney-general	Attorneys-general
Assistant Secretary Of State	Assistant Secretaries Of State
Notary Public	Notaries Public
Lady-in-waiting	ladies-in-waiting
lily-of-the-valley	lilies-of-the-valley
By adding -’s’ or -’es’  to the  word ending
Step-parent	Step-parents
Step-daughter	Step-daughters
Step-mother	Step-mothers
Maid-servant	Maid-servants
General Staff	General Staff(s)
Court-Martial	Court-Martials / Courts-Martial
Vice-Principal	Vice-Principals
Book-case	Book-cases
Go-between	Go-betweens
Has-been	Has-beens
Good-for-nothing	Good-for-nothings
Forget-me-not	Forget-me-nots
Higher-up	Higher-ups
Grown-up	Grown-ups
Mix-up	Mix-ups
Takeoff	Takeoffs
Armful	Armfuls
Handful	Handfuls
Cupful	Cupfuls
Mouthful	Mouthfuls
Tablespoonful	Tablespoonfuls
Blackboard	Blackboards
Bystander	Bystanders
Toothbrush	Toothbrushes
By changing both the  words
Man-servant	Men-servants
Man-driver	Men-drivers
Woman-writer	Women-writers
Woman-teacher	Women-teachers
Woman-doctor	Woman-doctors (Women-doctors)
By changing  words ‘man and woman’ into ‘men and women’
Fisherman	Fishermen
Workman	Workmen
Boatman	Boatmen
Man-of-war	Men-of-war
Saleswoman	Saleswomen
Workingwoman	Workingwomen
By adding -’s’ to the word ‘man’, when it refers to any ethnic group, race or civilian
Mussalman	Mussalmans
German	Germans
Norman	Normans
Brahman	Brahmans
Other phrases
Many Stops For Buses	Many Bus Stops
150 Trees With Oranges	150 Orange Trees

Rule No 14: In the case of letters, numbers, and abbreviations, we add an apostrophe and -’s’ to make them plural. 

Examples:

• Akshay, write your q’s and p’s clearly.
• Mohini, add two 8’s and subtract three 2’s.
• Ten M.A.’s and only two B.E.’s have attended the interview.

Rule No 15: Some Greek and Latin Nouns can form their plurals in the following manner:

1.Some nouns can be added –’es’ in place of –’is’ to make them plural

Examples:

analysis – analyses axis – axes basis – bases crisis – crises ellipsis – ellipses hypotheses – hypothesis

neurosis – neuroses oasis – oases paralysis – paralyses parenthesis – parentheses synopsis – synopses thesis – theses

2. Some Nouns that end in -’a’ can be added -’e’ to make the plural

Examples:

• antenna – antennae or antennas
• alga – algae
• formula – formulae
• larva – larvae
• nebula – nebulae
• vertebra – vertebrae 

3. Some nouns can be added –’i’ in place of –’us’ to make them plural

Examples:

• cactus – cacti
• focus – foci 
• fungus – fungi
• nucleus – nuclei
• radius – radii
• syllabus – syllabi
• terminus – termini 

4. Some nouns can be added –’a’ in place of –’um’ to make them plural

Examples:

• agendum (agenda) – agenda  (nowadays, agenda is used mostly as a singular form)
• aquarium – aquaria or aquariums
• bacterium – bacteria
• curriculum – curricula
• corrigendum – corrigenda
• datum – data
• erratum – errata
• forum – fora
• gymnasium – gymnasia or gymnasiums
• maximum – maxima or maximums
• medium – media
• memorandum – memoranda or memorandums
• millennium – millennia
• moratorium –  moratoria or moratoriums
• podium – podia or podiums  
• referendum – referenda or referendums
• stratum – strata

4. Some nouns can be added –’ices’ in place of –’ex/ix’ to make them plural

Examples:

• appendix – appendices or appendixes
• index – indices or indexes
• matrix – matrices
• vertex – vertices

6. Some nouns can be added –’a’ in place of –’on’ to make them plural

Examples:

• automaton – automata or automatons
• criterion – criteria
• ganglion – ganglia or ganglions
• polyhedron – polyhedra
• phenomenon – phenomena

7. Some nouns that end in –’ma’ can be added –’ta’ to make them plural

Examples:

• dogma – dogmata
• stigma – stigmata

8. The following words are from French:

Examples:

• madame (madam) –  mesdames 
• monsieur – messieurs

Greek and Latin Nouns Worksheets

Rule No 16: Some Nouns have two plural forms each with a different meaning.

Examples:

Singular	Plural	Meaning
brother	brothers	sons of the same parent
	brethren	members of a society or a community
Cloth	cloths	pieces of cloth
	clothes	dresses or garments
Die	dies	stamps for coining
	dice	small cubes used in games
Index	indexes	tables of contents to books
	indices	signs used in algebra
Penny	pennies	number of coins
	pence	amount in value
fish	fish	denote the same kind of two or more fish
	fishes	denote the different kinds of fish
genius	geniuses	intelligent or talented persons
	genii	spirits or ghosts

Rule No 17: Some Nouns have two meanings in the singular but only one in the plural:

Examples:

Singular	Meaning	Plural	Meaning
people	1. nation 2. men or women	peoples	nations
powder	1.dust 2. a dose of medicine	powders	doses of medicine
practice	1. habit  2. exercise of a profession	practices	habits
light	1.a lamp 2. radiance	lights	lamps

Rule No 18: Some nouns have one meaning in the singular, but two in the plural. 

Examples:

Singular	Meaning	Plural	Meaning
arm	upper limb	arms	1.upper limbs 2.weapons
colour	hue	colours	1.hues 2. the flags of a regiment
custom	habit	customs	1.habits 2.duties levied on imports
manner	method	manners	1.methods 2.correct behaviour
minute	A unit of time	minutes	1.units of time 2.proceedings of a meeting
moral	a moral lesson	morals	1.moral lessons 2.conduct
number	a quantity	numbers	1.quantities 2.verses
effect	result	effects	1) results 2) property
pain	suffering	pains	1.suffering 2.care, exertion
quarter	fourth part	quarters	1.fourth parts 2.lodgings
spectacle	a sight	spectacles	1.sights 2.eye-glasses
premise	proposition	premises	1. propositions  2. buildings
letter	1.a letter of the alphabet 2.epistle	letters	1.letters of the alphabet 2.epistles 3.literature

Rule No 19: Some nouns have different meanings in the singular and in the plural. 

Examples:

Singular	Meaning	Plural	Meaning
advice	counsel	advices	information
air	atmosphere	airs	affected manners
authority	power	authorities	persons in power
beef	flesh of ox	beeves	bulls, cattle and cows
blind	unable to see because of injury, disease, or a congenital condition	blinds	a screen for a window
good	benefit, well-being	goods	merchandise
compass	extent, range	compasses	in an instrument for drawing circles
iron	a metal	irons	fetters
physic	medicine	physics	natural science
character	the mental and moral qualities distinctive to an individual.	characters	a person in a novel, play, or film
respect	regard	respects	compliments
force	strength	forces	troops
return	coming back	returns	statistics
vesper	evening	vespers	evening prayers
sand	a kind of matter	sands	a desert
wood	the hard fibrous material that forms the main substance of the trunk or branches of a tree or shrub, used for fuel or timber.	woods	a small forest

Rule No 20: Some nouns are normally used in the plural. 

1.Proper Nouns:

India, Telangana, Warangal, Ashoka, Mary, Ganga etc

Note.1 When a Proper Noun is used in the plural, it becomes a Common Noun.

He is a Bruce Lee in fighting.

Kalidasa is called the Shakespeare of India

Note.2 But Some Nouns can be used in Plural like

The United States of America, The Alps, The Himalayas etc.,

2.Abstract Nouns:

Hope, charity, love, kindness, friendship, death, beauty etc.,

Note: When the Abstract Noun is used in the plural, it becomes a Common Noun.

Truly, the beauties of Kashmir are enticing.

3.Material Nouns:

Copper, iron, tin, wood, glass, rice, oil etc.,

Note: When a Material Noun is used in the plural, it becomes a Common Noun

Examples:

He does not have any coppers with him. (copper coins)

The convict has been found in irons. (fetters)

Last summer, we enjoyed ourselves in the nearby woods. (forests)

• Types of Nouns
• Proper Nouns
• Common Nouns
• Collective Nouns
• Nouns of Multitude
• Material Nouns
• Abstract Nouns
• Compound Nouns
• The Noun – Case
• Gender of the Noun
• Possessive Nouns
• A list of Partitives
• Appositive
• List of Countable and Uncountable Nouns
• Countable and Uncountable Nouns

Nouns are a diverse group of words, and they are very common in English. Nouns refer to things—the names of people (Dr. Sanders, lawyers), places (Kansas, factory, home), things (scissors, sheet music, book), or ideas (love, truth, beauty, intelligence).

Pluralization

English has both regular and irregular plural nouns. Regular plurals follow this rule (and other similar rules), but irregular plurals are, well, not regular and don’t follow a “standard” rule.

Regular Plurals

Let’s start with regular plurals: regular plural nouns use established patterns to indicate that there is more than one of a thing. As was mentioned earlier, we add the plural suffix –s or –es to most words (cats, zebras, classes, foxes, heroes). Remember that when words have a foreign origin (e.g., Latin, Greek, Spanish), we just add the plural suffix –s (tacos, avocados, maestros).

When a word ends in y and there is a consonant before y, we change the y to i and add –es. Thus sky becomes skies. However, if the y follows another vowel, you simply add an –s. (donkeys, alloys). When a word ends in –f or –fe, we change the f to v and add –es (calves, leaves). However, if there are two terminal fs, or if you still pronounce the f in the plural, you simply add an –s (cliffs, chiefs).

Irregular Plurals

Irregular plurals, unlike regular plurals, don’t necessarily follow any particular pattern—instead, they follow a lot of different patterns. For this reason, irregular plurals require a lot of memorization. If you’re ever in doubt, the dictionary is there for you.

The first kind of irregular plural we’ll talk about is the no-change or base plural. In these words, the singular noun has the exact same form as the plural (sheep, fish, deer, moose). Most no-change plurals are types of animals.

The next type of irregular is the mid-word vowel change. This includes words like tooth, man, and mouse, which become teeth, men, and mice.

Note: The plural for a computer mouse (as opposed to the fuzzy animal) can either be mice or mouses. Some people prefer mouses as it creates some differentiation between the two words.

We also have the plural –en. In these words, –en is used as the plural ending instead of –s or -es.

• child → children
• ox → oxen
• brother → brethren
• sister → sistren

Note: Brethren and sistren are antiquated terms that you’re unlikely to encounter or use; however, since these are the only four words in English that use this plural, all four have been included above.

The last category of irregular plurals is borrowed words. These words are native to other languages (e.g., Latin, Greek) and have retained the pluralization rules from their original tongue.

Singular –us; Plural –i	cactus → cacti	fungus → fungi	syllabus → syllabi
Singular –a; Plural –ae	formula → formulae	vertebra → vertebrae	larva → larvae
Singular –ix, –ex; Plural –ices, –es	appendix → appendices	matrix → matrices	index → indices
Singular –on, –um; Plural –a	bacterium → bacteria	criterion → criteria	medium → media
Singular –is; Plural –es	thesis → theses	analysis → analyses	crisis → crises

The rules presented in the table above are almost always followed, but as a borrowed word becomes more popular in its usage, it can be adopted into regular pluralization. For example, formulas and appendixes are accepted words in formal situations. Also, in informal speech, cactuses and funguses are acceptable.

Note: Because of the word’s history, octopuses is preferred to octopi, but octopi is an accepted word.

There are many to categorize nouns: concrete vs. abstract nouns, common vs. proper nouns, count vs. noncount nouns, and compound vs. non-compound nouns. Let’s take a look at each of these classifications and see exactly what they each mean.

Concrete vs. Abstract Nouns

Concrete nouns are things you can touch, see, hear, or otherwise sense, like book, light, or warmth.

Abstract nouns, on the other hand, are (as you might expect) abstract concepts that can’t be perceived through the senses, such as time and love.

• concrete noun: rock
• abstract noun: justice

Common vs. Proper Nouns

Common nouns are generic words, like tissue or watch. They are always lowercase (unless they begin a sentence). A proper noun, on the other hand, is the name of a specific person or thing, like the name John or the brand name Kleenex or Rolex. Proper nouns are always capitalized.

• common noun: girl
• proper noun: Ester

Count vs. Non-count Nouns

Count nouns are nouns which can be counted. Count nouns can be associated with a numerical value (three whales) in both its singular and plural forms (one fox, two foxes). In some cases, the number can be replaced by the words a, an or the (a fox, an owl, the squirrel).

If a noun cannot have a numerical value nor a plural form, it is called a non-count or mass noun. A person can give another person advice, but they cannot give three advices, because advice has no quantity.

Compound Nouns

A compound noun is a noun that is the result of joining together two other words (such as tooth and paste making toothpaste). Let us take for an example, the legend of Bigfoot.

A compound noun acts like one word, despite being a combination of two. Compound nouns can be classified as closed, hyphenated, or open. A closed compound takes the form of two words put together with no space such as daydream. A hyphenated compound includes two or more words joined by a hyphen such as dry-cleaning. An open compound is two words separated by a space but acting as one unit such as vacuum cleaner.

One common misconception is that compounds are hyphenated or open when one of the root words is longer than one syllable. However, it is important to remember that there are many open or hyphenated compound nouns that have of two single-syllable root words, such as six-pack and full moon.

Some compound nouns differ in writing style depending on who you ask, while others are recently developed, such as e-mail being shortened further to email.

Types of Compound Nouns

• Solid or Closed form: These compound nouns are defined as being a complete conjoining between the two words that form its makeup. Examples of closed compound nouns include: watermelon, underground, catfish and skydiving.
• Hyphenated form: Compound nouns that often appear in a hyphenated form are nouns that have suffixes (such as fund-rais(er) and wire-fasten(er)) and nouns that contain articles, conjunctions, or prepositions (such as mother-in-law or build-a-bear)
• Open or Spaced form: These are compound nouns that are considered to be compound even though they are separated by a space just like any two words. Despite looking like two independent words, they act together as one. Examples of open compound nouns are science fiction, peanut butter, and address book.

Hyphens are often considered a squishy part on language (we’ll discuss this further in Hyphens and Dashes). Because of this, usage differs and often depends on the individual choice of the writer rather than on a hard-and-fast rule. This means open, hyphenated, and closed forms may be encountered for the same compound noun, such as the triplets container ship/container-ship/containership and particle board/particle-board/particleboard. If you’re ever in doubt whether a compound should be closed, hyphenated, or open, dictionaries are your best reference.

Plurals

The process of making compound nouns plural has its own set of conventions to follow. In all forms of compound nouns, we pluralize the chief element of a compound word (i.e., we pluralize the primary noun of the compound).

• fisherman → fishermen
• blackbird → blackbirds
• brother-in-law → brothers-in-law

The word hand-me-down doesn’t have a distinct primary noun, so its plural is hand-me-downs.