Understanding Count Nouns, Mass Nouns, and Irregular Plurals

2 min read

One of the first things kids learn is how to make words plural. Even tiny toddlers can quickly tell the difference between “one cupcake” and “two cupcakes,” or “one cookie” and “two cookies.” Learning English is fun and delicious! But not all nouns can be made plural simply by adding an “s” to the end of the word. In fact, not all nouns have a separate plural form. Read on to learn the difference between count nouns, mass nouns, and — the trickiest of all — irregular plurals.

What Are Count Nouns?

The term “count noun” refers to any noun that can be counted. Basically, if a number can be put in front of it, it’s a count noun.

One dog → Three dogs

A coin → 10 coins

One suitcase → 14 suitcases

Countable nouns have both singular and plural forms, as seen in the above examples. An indefinite article, such as “a” or “an,” can be placed in front of a count noun. The vast majority of nouns fall in this category.

What Are Mass Nouns?

Some nouns simply refuse to be put in neat little categories. Nouns that cannot be counted are called “mass nouns.”

A mass noun is any substance, object, or concept that can’t be divided into separate parts. Usually, it has only a singular form. Take the mass noun “humility.” The amount of humility someone has can’t be quantified. And someone can’t have more than one humility. That’s why it’s a mass noun.

Indefinite articles don’t belong with mass nouns. Instead, explain the quantity by using a descriptive word in front of the noun.

A grain of rice

A pint of blood

A bar of gold

These mass nouns are always singular, so use a singular verb with them.

Kerosene is needed for the fire.

Her jewelry is on the table.

Laughter is the best medicine.

The same is true for words like “gymnastics,” “rabies,” or “mathematics.” They may end in an “s” but are still treated as singular mass nouns.

To further confuse things, some nouns are both countable and mass. For example, the mass noun “fish” is a type of meat. But the count noun “fish” is for creatures that make their home in the water. It would be correct to say either, “Fish is being served for dinner” or “Fish are swimming in the river.”

What About Irregular Plurals?

Count nouns can be either singular or plural. Mass nouns are almost always singular. Pretty easy.

But, of course, some nouns defy categorization. These are called “irregular plurals.” Even without advanced grammar skills, native speakers tend to learn these naturally. For example, the plural of “child” isn’t “childs,” it’s “children.”

Some irregular plural nouns change endings — for example, “knife” becomes “knives.” Others change vowel sounds, such as “foot” becoming “feet” and “man” turning into “men.” Then there are irregular plurals that seem to have no rhyme or reason. These words either change considerably or don’t change at all. There usually is a deep etymological history behind these irregulars, but it’s easiest to just memorize them as they come.

Person → People

Die → Dice

Sheep → Sheep

With irregular plurals, use the corresponding plural verb. That’s true even if the irregular plural doesn’t change between its singular and plural form.

All aircraft are receiving safety checks.

The moose are drinking from the stream.

Those salmon are swimming up the river.

Why do all these nouns have different rules? These exceptions have gradually evolved over the years for all kinds of historical and cultural reasons. As with a lot of things in the English language, you just have to learn the special cases and go with the flow.

Featured photo credit: Deagreez/ iStock

You Might Also Like:

Chat bubbles backgroundDaily QuestionWhat is an antonym for “stridulate”?

Start defining your knowledge

Get daily words and quizzes sent straight to your inbox!

By subscribing to Word Genius you are agreeing to our Privacy Policy and Terms of Use.