Irregular plural nouns — list — englishillustrated.com

What are irregular plural nouns?

Most nouns in English add -s or -es to make the plural. For example: cat → cats, box → boxes. But some nouns have special plural forms. These are called irregular plural nouns. They do not follow the regular rules. You must learn them by memory.

Common irregular plural nouns

Some very common nouns have completely different plural forms. Child becomes children. Person becomes people. Foot becomes feet. Tooth becomes teeth. Mouse becomes mice. These nouns are very important to learn because we use them often in English.

Other types of irregular plurals

Some nouns have the same form for singular and plural. For example: sheep, fish, and deer. Some nouns from other languages keep their original plural forms, like man → men or goose → geese. Pay attention when you read and listen to English. This helps you remember these special forms.

Irregular Plural Nouns — Complete List

Category	Singular	Plural	Note
Vowel-Change Plurals
Vowel change	man	men	a → e
Vowel change	woman	women	a → e
Vowel change	foot	feet	oo → ee
Vowel change	tooth	teeth	oo → ee
Vowel change	goose	geese	oo → ee
Vowel change	mouse	mice	ou → i
Vowel change	louse	lice	ou → i
Vowel change	dormouse	dormice	ou → i
-en Plurals
-en ending	ox	oxen	adds -en
-en ending	child	children	adds -ren
-en ending	brother	brethren	archaic/religious use
Zero-Change Plurals (Same Singular & Plural)
Zero change	sheep	sheep	no change
Zero change	deer	deer	no change
Zero change	fish	fish	"fishes" also accepted
Zero change	moose	moose	no change
Zero change	swine	swine	no change
Zero change	aircraft	aircraft	no change
Zero change	species	species	no change
Zero change	series	series	no change

Examples

The child has one book, but the children have many books.

Family · Very common irregular

I lost one tooth when I was six years old. Now I have all my teeth.

Body parts · Common irregular

There is one mouse in the kitchen and two mice in the bedroom.

Animals · Common irregular

The man walked to the park, but the men stayed home.

People · Very common irregular

She saw a goose by the lake and ten geese near the water.

Animals · Common irregular

One person came yesterday, but five people came today.

People · Very common irregular

When to use it

Talking about family

Use irregular plurals when you talk about family members and people.

"My friend has two children and her sister has three children."

Health and body

Use irregular plurals when you describe body parts or health problems.

"I brush my teeth two times every day."

Talking about animals

Many animal plurals are irregular. Learn them when you talk about nature.

"The farmer saw geese and sheep on his farm."

Everyday conversations

Irregular plurals are very common words you use every day.

"The people at work are very nice."

Common Mistakes

Wrong

The childs are playing in the park.

✓

Correct

The children are playing in the park.

Child is irregular. The plural is children, not childs.

Wrong

I have two tooths in my hand.

✓

Correct

I have two teeth in my hand.

Tooth is irregular. The plural is teeth, not tooths.

Wrong

There are three mans in the room.

✓

Correct

There are three men in the room.

Man is irregular. The plural is men, not mans.

Wrong

I saw five mouses in the garden.

✓

Correct

I saw five mice in the garden.

Mouse is irregular. The plural is mice, not mouses.

KEY TAKEAWAYS

What to Remember

Most English nouns add -s or -es to form the plural, but irregular nouns do not.
Common irregular plurals have completely different forms: child/children, person/people, foot/feet, tooth/teeth, mouse/mice.
Irregular plural nouns must be learned by memory because they do not follow standard rules.
You cannot predict irregular plural forms by applying regular pluralization rules to these nouns.
Learning irregular plurals is essential because these nouns are very frequently used in English.

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Regular plural nouns — adding -s and -es

Nouns that don't change in plural