Irregular Plural Nouns

While most nouns are easily made plural with a few simple changes, such as adding an “s” or “es” to the end of the word, there is one group of nouns that doesn’t seem to follow the rules.  They’re called irregular nouns and you guessed it…they don’t become plural the “regular” way.

No worries, though.  Here’s all the information you need to recognize and form irregular plural nouns.

What is an Irregular Plural Noun?

An irregular plural noun is an irregular noun in the plural form.  An irregular noun is a noun that becomes plural by changing it’s spelling in other ways than adding an “s” or “es” to the end of the word. This change can happen in a variety of ways.  Below you’ll find examples and guidelines to help you.

Examples of Irregular Plural Nouns


Some irregular nouns take on the plural form by first changing the last letter of the word before adding “s.” Words that end in “f” are a good example of this case. To make such a word plural, you change the “f” to “ve” and add an “s.”


Plural nouns that end in ves:

  • More than one elf = elves
  • More than one calf = calves
  • More than one knife = knives
  • More than one loaf = loaves
  • More than one shelf = shelves
  • More than one wolf = wolves
  • More than one loaf = loaves

Irregular nouns made plural by changing vowels, changing the word, or adding a different ending:

  • More than one man = men
  • More than one person = people
  • More than one mouse = mice
  • More than one child = children
  • More than one foot = feet
  • More than one goose = geese
  • More than one tooth = teeth
  • More than one louse = lice
  • More than one cactus = cacti
  • More than one appendix = appendices
  • More than one ox =oxen


Some irregular plural nouns have the same spelling as their singular form such as scissors, pants, bison, deer, and sheep.And then some animal nouns become plural by keeping the same spelling as the singular form or by adding an s or es.


  • More than one cod = cod or cods
  • More than one shrimp = shrimp or shrimps
  • More than one fish = fish or fishes
  • More than one quail = quail or quails

Like most things, learning the rules for irregular plural nouns takes practice.  Once you put these guidelines to work for you, you’ll find it much easier than you thought.