Plural forms of Nouns
1. The plural form of most nouns is created simply by adding the letter s.
snake = snakes, ski = skis, Barrymore = Barrymores
2. Words that end in -ch, x, s or s-like sounds, however, will require an -es for the plural:
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witch = witches, bus = buses, box = boxes, gas = gases, Jones = Joneses, kiss = kisses
3. There are several nouns that have irregular plural forms. Plurals formed in this way are sometimes
called mutated (or mutating) plurals.
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one child = children
one woman = women
one goose = geese
one barracks = barracks
ox – oxen
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one man = men
one person = people
one mouse = mice
one deer = deer
child – children
4. And, finally, there are nouns that maintain their Latin or Greek form in the plural.
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one nucleus = nuclei
one syllabus = syllabi
one focus = foci
one fungus = fungi
one cactus = cacti (cactuses is acceptable)
one thesis = theses
one crisis = crises
one phenomenon = phenomena
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one index = indices (indexes is acceptable)
one appendix = appendices (appendixes is
acceptable)
one criterion = criteria
datum – data
medium – media
stimulus – stimuli
formula – formulae
5. A handful of nouns appear to be plural in form but take a singular verb:
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The news is bad.
Gymnastics is fun to watch.
Economics/mathematics/statistics is said to be difficult.
6. Special Cases. With words that end in a consonant and a y, you'll need to change the y to an i and add es.
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one baby = babies
one gallery = galleries
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one reality = realities
fly – flies army - armies
This rule does not apply to proper nouns:
 one Kennedy = Kennedys
 Notice the difference between this and galleys, where the final y is not preceded by a consonant,
day – days, play – plays, key – keys, mon key – monkeys, toy - toys)
Words that end in o create special problems.
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one potato = potatoes
one hero = heroes
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cargo – cargoes
echo - echoes
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and for words where another vowel comes
before the o . . .
one stereo = stereos
cuckoo – cuckoos
portfolio – portfolios
. . . however . . .
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one memo = memos
one cello = cellos
one piano – pianos
solo – solos
photo – photos
!!! mosquito – mosquitos OR mosquitoes
Plurals of words that end in -f or -fe usually change the f sound to a v sound and add s or -es.
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one knife = knives
one leaf = leaves
one hoof = hooves
one life = lives
one self = selves
one elf = elves
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thief – thieves
calf – calves
half – halves
shelf – shelves
wolf – wolves
wife – wives
!!! scarf – scarfs OR scarves
There are, however, exceptions: one dwarf = dwarfs, one roof = roofs
7. The vast majority of compound nouns form their plurals by adding -s to the principal word (shown
in bold) in the compound. Mainly it is a Noun.
Examples:
He now has two mothers-in-law. (plural of mother-in-law).
Editor-in-chief – editors-in-chief, Brother-in-law – brothers-in-law, Looker-on – lookers-on
Lady-bird – lady-birds (2 Nouns, so we add ending to the last one)
When there is no obvious principal word, add -s (or -es) to the end of the compound.
Forget-me-nots make a wonderful present. (plural of forget-me-not)
merry-go-round – merry-go-rounds