General Rule. The plural of nouns are most commonly formed by the addition of "s".
Example:
SINGULAR PLURAL
door doors
obligation obligations
pencil pencils
ruler rulers
Nouns Ending in "x," "ch", "sh," or "ss" The plural of nouns ending in "x," "ch", "sh," or "ss" The plural of nouns ending or "x," "ch", "sh", or "ss" are form by the addition of "es."
SINGULAR PLURAL
box boxes
church churches
bush bushes
business businesses
Nouns Ending in "y". When a final "y" is preceded by a vowel, the plural is formed by the addition of "s". But when the final "y" is preceded by a consonant, the "y" changes to "i" and "es" is added.
Example:
SINGULAR PLURAL
attorney attorneys
delay delays
company companies
courtesy courtesies
Exception: Proper names ending in "y", Mary, Mary; Henry Henry's.
Compound Nouns.
Compound nouns written with hyphens form their plurals by the addition of "s" to the principal word.
Examples:
SINGULAR PLURAL
court-martial courts-martial
editor-in-chief editors-in-chief
hanger-on hangers-on
son-in-law sons-in-law
In some instances both parts of a compound noun are used with the plural
Examples:
SINGULAR PLURAL
manservant menservants
Knight Templar Knights Templars
Nouns Ending in "t" or "f" or "fe". The plurals of most nouns ending "f" or "t" are formed by the addition of "s".
SINGULAR PLURAL
cuff cuffs
belief beliefs
dwarf dwarfs
handkerchief handkerchiefs
chef chefs
safe safes
But in some nouns ending in "f" or "fe" the "f" changes to "v" and the word ends with "ves".
Example:
SINGULAR PLURAL
calf calves
half halves
knife knives
leaf leaves
life lives
loaf loaves
scarf scarves (also scarfs)
shelf shelves
thief thieves
wharf wharves
wife wives
wolf wolves
Nouns ending in "o". The plurals of nouns ending in "o" preceded by a vowel are formed by the addition of the letters "s".
Examples:
SINGULAR PLURAL
cameo cameos
duo duos
folio folios
trio trios
The plurals of most of other nouns associated with music, are formed by the addition of the letters."s".
Examples
SINGULAR PLURAL
albino albinos
banjo banjos
dynamo dynamos
Eskimo Eskimos
kimono kimonos
memento mementos
piano pianos
soprano sopranos
tobacco tobaccos
zero zeros
The plurals of some nouns ending in "o" preceded by a consonant are formed by the addition of "es".
Examples:
SINGULAR PLURAL
buffalo buffaloes
calico calico s
cargo cargoes
desperado desperadoes
domino dominoes
echo echoes
embargo embargoes
hero heroes
mosquito mosquitoes
motto mottoes
mullato mullatoes
negro negroes
potato potatoes
tomato tomatoes
tornado tornadoes
torpedo torpedoes
veto vetoes
volcano volcanoes
