The vast majority of nouns in the English language are made plural by adding an “s” or “es” to the end of the word. For example, book changes to books when made plural. However, certain nouns have irregular plurals that do not behave in this standard way. And even though most irregular plural nouns follow a pattern, there are several patterns to watch out for, as you'll see in this list of irregular plural nouns.
Irregular plural nouns don’t adhere to specific rules; therefore, it’s prudent to study them or search for accurate pluralization in the dictionary. Lack of definite rules makes it challenging to understand them. So, you must devote your time to study and memorize them. Otherwise, you’re bound to error when making use of irregular nouns in plural form.