Irregular Plurals of Nouns

Blog Image


Although most nouns have plurals formed according to regular rules, some nouns have unusual, or irregular plurals. This article will introduce the most common ones, so that you can learn them.

Types of irregular plural

There are many types of irregular plural, but these are the most common:

Noun typeForming the pluralExample
Ends with -feChange f to v
Add -s
knife arrow to the right knives
life arrow to the right lives
wife arrow to the right wives
Ends with -fChange f to v
Add -es
half arrow to the right halves
wolf arrow to the right wolves
loaf arrow to the right loaves
Ends with -oAdd -espotato arrow to the right potatoes
tomato arrow to the right tomatoes
volcano arrow to the right volcanoes
ends with -usChange -us to -icactus arrow to the right cacti
nucleus arrow to the right nuclei
focus arrow to the right foci
ends with -isChange -is to -esanalysis arrow to the right analyses
crisis arrow to the right crises
thesis arrow to the right theses
ends with -onChange -on to -aphenomenon arrow to the right phenomena
criterion arrow to the right criteria
ALL KINDSChange the vowel
Change the word
Add a different ending
man arrow to the right men
foot arrow to the right feet
child arrow to the right children
person arrow to the right people
tooth arrow to the right teeth
mouse arrow to the right mice
UnchangingSingular and plural
are the same
fish (sometimes)
Course Image

Free English Placement Test

Check your Score - Try our Free English Quiz + Get a Free Bonus