Irregular Plural Nouns – Learn Patterns to Remember the Tricky Ones

In English, when we talk about more than one of something, we usually make the noun plural such as one book, two books, one cat, three cats.  These are regular plurals and we simply add -s or -es at the end to make their plurals. However, not all nouns follow the same rule. Some nouns change in different ways and they are known as irregular plural nouns. 

In this article, you will learn what irregular plural nouns are, the rules, and example sentences using these nouns in context.

What are Irregular Plural Nouns?

Irregular plural nouns are nouns that do not follow the standard rule of adding -s or -es to form the plural. Instead, they change their spellings, change vowels inside the word, or something stays exactly the same. These kinds of plural nouns are called irregular plural nouns and they are commonly used in everyday English.

Common Examples of Irregular Plural Nouns

Here are some simple examples to help you understand better:

The most common irregular plurals

Nouns ending in -f and -fe

In case of a singular noun that ends in -f, then we replace -f with -ves to make a plural noun. See the examples below:

Exceptions: roof → roofs, proof → proofs, chief → chiefs

Nouns ending in -o

If a singular nouns ends in -o, then we add -es at the end to make plural nouns.

Some -o nouns take only -s: photo → photos, piano → pianos

Noun that change vowels

Irregular Nouns that change substantially

Irregular nouns that do not change at all

Examples:

• I have seen several deer when walking in the woods near here.
• How many shrimps did you catch?
• NASA has made several different types of spacecraft in its fifty-nine-year history

Aircraft, watercraft, hovercraft, and spacecraft are all the same, whether singular or plural.

Plural of Latin and Greek Words

Nouns ending in -us

Irregular formation of nouns ending in -is

Irregular formation of nouns ending in -on

Irregular formation of nouns ending in -um

Irregular formation of nouns ending in -ix

Examples:

Conclusion

These rules of irregular plural nouns must simply be memorized, although it is helpful to understand the patterns first in order to master them. 

FAQs About Irregular Plural Nouns

What makes a plural noun irregular?

If the noun doesn’t become plural by simply adding -s or -es, it is called an irregular plural noun.

I hope this article hepled you to learn what are irregular plural nouns, how to form them, rules, and examples used in sentences.

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