The Grammaring Guide to English Grammar with Exercises

Irregular plural forms

The plural of a noun is usually formed by adding -s to the singular form:

mistake

»

mistake

s

For certain nouns, if the singular noun ends in -f or -fe, the plural ending is -ves:

elf

»

el

ves

knife

»

kni

ves

thief

»

thie

ves

hoof

»

hoo

ves

But there are nouns which do not follow this rule:

cliff

»

cliff

s

chief

»

chief

s

cuff

»

cuff

s

roof

»

roof

s

A number of nouns have irregular plural forms:

child

»

child

ren

ox

»

ox

en

foot

»

f

ee

t

goose

»

g

ee

se

tooth

»

t

ee

th

mouse

»

m

ic

e

louse

»

l

ic

e

man

»

m

e

n

woman

»

wom

e

n

Nouns of Latin or Greek origin may keep their original plural forms:

crisis

»

cris

es

bacterium

»

bacteri

a

appendix

»

appendi

ces

formula

»

formul

ae

Quotes:

Men for the sake of getting a living forget to live. - Margaret Fuller

Children make you want to start life over. - Muhammad Ali

Wise men speak because they have something to say; fools because they have to say something. - Plato