English countable nouns have two numbers the singular and the plural.
The main types of the plural forms of English nouns are as follows:
1.1.1. The general rule for forming the plural of English nouns is by adding the ending s ( -es) to the singular; -s is pronounced in different ways:
[ iz ] after sibilants [z], [s], [ʒ], [ʃ], [dʒ], [tʃ]: noses, horses, bridges.
[ z ] after voiced consonants other than sibilants and after vowels: flowers, beds, doves, bees, boys.
[ s ] after voiceless consonants other than sibilants: caps, books, hats, cliffs.
1.1.2. If the noun ends in s, -ss, -x, -sh, -ch, or tch, the plural is formed by adding es to the singular:
bus buses
glass glasses
box boxes
brush brushes
bench benches
match matches
1.1.3. If the noun ends in a consonant and y, the letter y usually changes into i before es:
sky - skies
fly flies
army armies
lady ladies
But the letter y remains unchanged before -s :
a)in proper names:
Mary Marys
Kennedy the Kennedys
February - Februarys
b) in compound nouns:
stand-by stand-bys
lay-by lay-bys
c) after vowels:
day days
key keys
toy - toys
1.1.4. If the noun ends in a consonant and o, the plural is generally formed by adding es.
cargo cargoes
hero heroes
potato potatoes
echo echoes
The following nouns ending in o form the plural in s and not in es:
a) all nouns ending in a vowel and o:
cuckoo cuckoos
portfolio portfolios
b) abbreviations:
photograph/photo photos
automobile/auto autos
kilogramme/kilo kilos
professional/pro pros
c) musical terms of Italian origin:
piano pianos
cello cellos
solo solos
concerto - concertos
d) proper nouns:
Eskimo Eskimos
Romeo Romeos
There are a few nouns ending in o which form the plural both in s and es:
mosquito mosquitos or mosquitoes
tornado tornados or tornadoes
volcano- volcanos or volcanoes
zero zeros or zeroes
1.1.5
a) The following nouns ending in f /-fe change it into - ves in the plural:
calf calves
elf elves
half halves
knife knives
leaf leaves
life lives
loaf loaves
self selves
sheaf sheaves
shelf - shelves
thief thieves
wife wives
wolf wolves
Other nouns ending in f/-fe do not change the final letter before s):
belief beliefs
chief chiefs
cliff cliffs
gulf gulfs
grief griefs
proof - proofs
roof - roofs
safe safes
still life still lifes
There are some nouns ending in f which have two forms in the plural:
Dwarf dwarfs or dwarves
Hoof hoofs or hooves
Scarf scarfs or scarves
Wharf wharfs or wharves
1.2. For historical reasons certain nouns form their plural differently.
1.2.1. There are seven nouns which form the plural by changing the root vowel:
man men
woman women
foot feet
tooth- teeth
goose geese
mouse mice
louse lice
1.2.2. There are two nouns which form the plural in en:
Ox oxen
Child children
1.2.3. With some nouns the plural form does not differ from the singular: deer, sheep, swine, fish, trout, salmon, craft (with the meaning of boat), aircraft, means, series, species, headquarters, works, crossroads, barracks etc.
E. g. This sheep looks small. All thosesheep are good.
The poor traveller was swallowed by a hugefish. We caught three fish that afternoon.
N O T E. The noun fish has the plural form fishes to denote different kinds of fish.
E. g. He studies the fishes of the Indian ocean.
1.3. Some words borrowed from Latin and Greek keep their Latin or Greek plural forms:
Singular
-is [is]
analysis
diagnosis
oasis
parenthesis
thesis
Plural
-es [i:z]
analyses
diagnoses
oases
parentheses
theses
-on [ǝn]/-um [ǝ]
criterion
phenomenon
datum
stratum
medium
bacterium
curriculum
-a [ǝ]
criteria
phenomena
data
strata
media
bacteria
curricula
-us [ǝs]
stimulus
nucleus
radius
corpus
genus
-i [ai]/ -ora [ǝrǝ]/ -era [ǝrǝ]
stimuli
nuclei
radii
corpora
genera
-a [ǝ]
-ae [i:]
antenna
vertebra
antennae
vertebrae
formula
-ix/ -ex [iks]
appendix
index
-ices [isi:z]
appendices ( or appendixes)
indices ( or indexes)
1.4. In compound nouns the plural is formed in different ways.
1.4.1. As a rule in compounds it is the second component that takes the plural form:
Housewife housewives
Toothbrush toothbrushes
Boy-scout boy-scouts
Maidservant maidservants
1.4.2. Compounds ending in man change it into men in spelling. In pronunciation, however, there is no difference between the singular and plural forms:
Policeman policemen
Postman postmen
Such nouns as German, Roman, etc. are not compounds, and therefore have regular plurals:
German Germans
Roman - Romans
1.4.3. Compounds in which the first component is man or woman have the plurals in both first and last components:
Man-servant men-servants
Woman-doctor women-doctors
C o m p a r e: man-killer man-killers (someone or something that kills men)/men-killers (men that kill)
1.4.4. In compounds which consist of two nouns connected by a preposition the first noun takes the plural form:
Editor-in-chief - editors-in-chief
Mother-in-law - mothers-in-law
Man-of-war - men-of-war
1.4.5. In compound nouns formed by a noun plus a preposition or an adverbial the plural ending is added to the noun:
Passer-by - passers-by
Looker-on - lookers-on
C O M P A R E: onlooker - onlookers, bystander - bystanders
1.4.6. If a compound does not include any nouns, the last element takes the plural ending:
Forget-me-not - forget-me-nots
Merry-go-round - merry-go-rounds
Break-down - break-downs
Grown-up - grown-ups
Stand-by - stand-bys
Press-up - press-ups
1.5. The wordpenny has two plural forms: pence (irregular) and pennies (regular).
Penceis used to denote a sum of money.
E.g. There are 100 pence in one pound.
The bus fare is 80 pence.
Pennies is used for individual coins.
E.g. Pennies are made of bronze.
Ive only got a few pennies left.
1.6. The following English nouns have regular plural forms, while the corresponding Russian nouns are always plural.
Watch - watches
Clock - clocks
Gate - gates
Sledge - sledges
Vacation - vacations
Funeral - funerals
Necklace - necklaces
Note:The noun fruit is uncountable.
E.g. Fruit is eaten either raw or cooked.
Try to eat plenty of fruit and vegetables.
Peaches are my favourite fruit.
However, it is used as a countable noun when it means different kinds of fruit.