Irregular Plural Nouns Part One

The plural forms of most English nouns are made by adding –s to the singular form. “Forms” and “nouns” from the previous sentence are perfect examples. However, many commonly-used English nouns have irregular plural forms. Some of these nouns follow alternate pluralization rules. Other nouns are identical in both singular and plural forms. Still other nouns have completely unique singular and plural forms.


–F/FE to VES

Nouns ending in –f or –fe preceded by consonant or a single vowel change to –ves in the plural:


Singular Plural
calf calves
dwarf dwarves
hoof hooves
knife knives
leaf leaves
life lives
self selves
thief thieves
wife wives
wolf wolves


If a noun ending in –f /–fe is preceded by two consecutive vowels, just add –s:


Singular Plural
chief chiefs
proof proofs
spoof spoofs



­O to OES

Some nouns ending in –o change to –oes in their plural forms while other simply take –s. Here are several commonly-used examples of each.


–O to –OES
Singular Plural
domino dominoes
echo echoes
hero heroes
mosquito mosquitoes
potato potatoes
tomato tomatoes
zero zeroes


–O to –OS
Singular Plural
embryo embryos
patio patios
solo solos
studio studios
zoo zoos


Some –o words can take either ­–o or –oes in the plural:


–O to –OS or –OES


Singular Plural
cargo cargo(e)s
flamingo flamingo(e)s
halo halo(e)s
tornado tornado(e)s
volcano volcano(e)s


Note: Nouns with a vowel before the final –o always take –s in the plural.



Nouns Ending in CH, S, SH, X, or Z

When a noun ends in –ch, –s, –sh, –c, or –z, add –es to form the plural:


Singular Plural
bus buses
church churches
fox foxes


Note: Nouns where the –ch is pronounced as a “K” are an exception to this rule. To form the plural of these nouns, just add –s. For example, the plural of “stomach” is “stomachs.”


–Y to –IES

Nouns ending in a consonant plus –y drop the ­–y and add –ies in the plural form:


Singular Plural
activity activities
daisy daises
family families



Changing Vowel Sounds

Several English nouns change vowel sounds in their plural forms. Commonly-used vowel changing nouns include:


Singular Plural
foot feet
goose geese
mouse mice
(wo)man (wo)men
tooth teeth



Identical Singular and Plural

Finally, some nouns (especially the names of animals) do not change from the singular to the plural:


Singular Plural
deer deer
fish fish
sheep sheep


That’s all for this lesson. Next time we’ll look at words with foreign origins that have retained their plural forms from their original languages.