The majority of nouns in English spell their plural by simply adding a final -s. Nouns that are noncount or abstract (e.g., cheese, sugar, honesty, intelligence) generally take a singular verb, but in some instances can be plural, in which case they follow the rules for plural based on their spelling. Also, there are some categories of words which are only plural, even though their spelling does not reflect this. They are included in a list at the end of this page. For irregular count nouns and nouns that have been borrowed from other languages, the rules are as follows:

Variations of the final -s rule:

• Nouns that end with -s, -z, -x, -sh, -ch 

Add -es

glass/glasses, buzz/buzzes, box/boxes, bush/bushes, switch/switches
 

• Nouns that end in -o 

Add -es

potato/potatoes, echo/echoes, hero/heroes

exceptions: studio/studios, piano/pianos, kangaroo/kangaroos, zoo/zoos

either: buffalo/buffalo(e)s, cargo/cargo(e)s, motto/motto(e)s, 

volcano/volcano(e)s



• Nouns that end in a consonant + -y 

Change -y to -i and add -es

baby/babies, spy/spies, poppy/poppies



• Nouns that end in -f, or -fe 

Change the -f to -v and add -es


shelf/shelves, wolf/wolves, knife/knives, wife/wives

• Singular ends in -is 

Plural ends in -es

analysis/analyses, basis/bases



• Singular ends in -um 

Plural ends in -a

datum/data, curriculum/curricula



• Singular ends in -on 

Plural ends in -a

criterion/criteria, phenomenon/phenomena



• Singular ends in -a 

Plural ends in -ae

formula/formulae, antenna/antennae



• Singular ends in -ex or -ix 

Plural ends in -ices

appendix/appendices, index/indices



• Singular ends in -us 

Plural ends in -i

focus/foci, stimulus/stimuli



• Singular ends in -us 

Plural ends in -a

corpus/corpora, genus/genera



• Singular ends in -eau 

Plural ends in -eaux

bureau/bureaux, beau/beaux

• Things that come in pairs 

Tools: glasses, scissors, binoculars, forceps, tongs, tweezers

Clothes: jeans, pants, pajamas, shorts, trousers



• Nouns that end in -s but have no singular (aggregate nouns) 

accommodations, amends, archives, arms (weapons), bowels, intestines, 

brains (intellect), clothes, communications, congratulations, contents, 

stairs, thanks, goods



• Nouns that are plural but do not end in -s 

people, police, cattle, people