100 Irregular Plural Nouns in English

Most English nouns form their plural by adding either -s (books, bands, bells) or -es (boxes, bunches, batches). These plural forms are said to follow a regular pattern.

Irregular Plural Nouns

"The Penguin Writer's Manual"

"There are no easy rules, unfortunately, for irregular plurals in English. They simply have to be learnt and remembered."

Not all nouns conform to the standard pattern. In fact, some of the most common English nouns have irregular plural forms, such as woman/women and child/children.

In addition, several nouns have alternative plurals, one regular and the other irregular.

In regard to these alternative forms, there are no strict rules to guide our use of them.

"The Cambridge Encyclopedia of the English Language"

"People have to learn which form to use as they meet the words for the first time, and must become aware of variations in usage. When there is a choice, the classical [irregular] plural is usually the more technical, learned, or formal, as in the case of formulas vs. formulae or curriculums vs. curricula. Sometimes, alternative plurals have even developed different senses, as in the cases of (spirit) mediums vs. (mass) media, or appendixes (in bodies or books) vs. appendices (only in books)."

As you'll see in the list that follows, many words with irregular plurals are loanwords that have kept their foreign plural forms (or at least held on to those forms as alternatives to regular English plurals).

100 Irregular Plural Nouns List

In the list below, you'll find singular noun forms in the left column and the corresponding plural forms in the right column. When a noun has more than one plural form, the irregular one appears first, though that doesn't necessarily mean that the irregular form is more widely accepted than the regular form.

Sources

Crystal, David. "The Cambridge Encyclopedia of the English Language." 3rd Edition, Cambridge University Press, January 24, 2019.
Manser, Martin. "Penguin Writers Manual." Penguin Reference Books, Stephen Curtis, Paperback, International Edition, UK ed. edition, Penguin UK, August 24, 2004.