Singular and Plural Nouns
Learn how nouns change to show whether they name one person, place, thing or idea, or more than one.
One or more than one?
Nouns change form to show number.
A singular noun names one person, place, thing or idea. A plural noun names more than one.
Most nouns form their plural by adding -s or -es to the singular form, but a number of nouns follow different patterns.
Recognising singular and plural forms affects spelling, verb agreement and the choice of words such as this, these, a and some.
Before you begin
Singular and plural forms are still nouns.
This lesson looks at how nouns change in number. It does not change what a noun is or how it functions in a sentence.
If you would like to review what nouns are and how they work, begin with the Nouns lesson.
The central idea
The singular form names one. The plural form names more than one.
Compare the two forms and notice how the spelling changes.
01
Singular Nouns
A singular noun names exactly one person, place, thing or idea.
book
city
child
idea
02
Plural Nouns
A plural noun names more than one person, place, thing or idea.
books
cities
children
ideas
The useful question is: How many does the noun name?
one dog → singular
two dogs → plural
a child → singular
several children → plural
The number of items or people the noun refers to decides whether the singular or plural form is correct.
Forming regular plurals
Most plural nouns are formed by adding -s or -es.
Add -s
book → books
car → cars
idea → ideas
This is the most common way to form a plural noun.
Add -es after -s, -ss, -sh, -ch, -x or -z
bus → buses
glass → glasses
brush → brushes
box → boxes
The extra syllable created by -es makes the plural easier to pronounce after these endings.
Consonant + y → change y to i and add -es
city → cities
baby → babies
country → countries
When a noun ends in a consonant followed by -y, the y changes to i before -es is added. A vowel before -y does not change: day → days.
Some nouns ending in -o add -es
tomato → tomatoes
hero → heroes
photo → photos
Not every noun ending in -o follows this pattern. Photo, piano and kilo simply add -s.
Irregular plurals
Some plural nouns do not follow the regular -s or -es pattern.
Vowel changes inside the word
man → men
woman → women
foot → feet
tooth → teeth
Two mice ran across the kitchen floor.
Endings that do not use -s
child → children
person → people
ox → oxen
Nouns with the same singular and plural form
sheep → sheep
fish → fish
deer → deer
series → series
One sheep stood alone; the rest of the sheep stayed near the fence.
Plurals from other languages
cactus → cacti
criterion → criteria
phenomenon → phenomena
These plural forms come from Latin or Greek. Some, such as cactuses, also have a regular alternative in everyday use.
Nouns with only one form
Some nouns are always plural in form, and others only look plural.
Always plural in form
scissors
trousers
glasses
jeans
My scissors are in the top drawer.
These nouns name a single item made of two joined parts. They take a plural verb and have no separate singular form.
Plural in form but singular in meaning
news
mathematics
physics
The news is on at six o’clock.
These nouns end in -s, but they name a single subject or body of information and take a singular verb.
Plurals of compound nouns
Compound nouns usually pluralise their main word.
A compound noun is made of two or more words. The plural ending is usually added to the word that names the main person or thing.
Plural added to the main word
mother-in-law → mothers-in-law
passer-by → passers-by
runner-up → runners-up
Both runners-up received a small prize.
Plural added to the end of the whole word
toothbrush → toothbrushes
classroom → classrooms
When a compound noun is written as one word, the plural ending is added at the end, following the usual spelling rules.
A useful decision guide
Check how many, then check the spelling pattern.
01
Does the noun name one or more than one?
This decides whether the singular or plural form is needed.
one city
three cities
02
What does the noun end in?
The final letters decide whether to add -s, -es or change -y to -ies.
bus → buses
city → cities
03
Is the noun irregular?
Some common nouns must be learned individually rather than by rule.
child → children
foot → feet
04
Does the form match the meaning?
Some nouns end in -s but name one thing, such as news. Others have no separate singular form, such as scissors.
Common mistakes
Do not assume every plural noun follows the same rule.
A final -s does not always mean the noun is plural.
news → singular meaning
mathematics → singular meaning
The ending must be checked against the meaning, not read on its own.
Not every noun ending in -y follows the same pattern.
city → cities
day → days
The letter before -y decides the pattern. A consonant before -y changes to i; a vowel before -y does not change.
Irregular plurals cannot be formed by adding -s.
Not: mouses
Correct: mice
These forms must be learned individually rather than produced with a spelling rule.
Check your understanding
Singular or plural?
Choose the correct form for the highlighted noun.
The children are playing outside.
✅ Exactly! Children is the irregular plural of child.
❎ Not quite. This noun names more than one child.
Child does not add -s to form its plural.
The news was surprising.
✅ Exactly! News ends in -s but names one thing.
❎ Not quite. Look at the verb was, which is singular.
Several fish swam past the boat.
✅ Exactly! Fish can be plural even though the form does not change.
❎ Not quite. Look at the word several, which signals more than one.
A city can change a great deal in ten years.
✅ Exactly! City names one place here.
❎ Not quite. Look at the article a, which is used with one item.
Choose the best explanation
Select the sentence that explains the noun correctly.
Why does city become cities in the plural?
✅ Exactly! A consonant before -y changes to -ies in the plural.
❎ Not quite. Look at the letter directly before the final -y.
Why is scissors always plural in form?
✅ Exactly! Nouns like scissors name a single two-part item and have no separate singular form.
❎ Not quite. Think about the shape of the object the noun names.
Which pair shows a regular plural and an irregular plural?
✅ Exactly! Books follows the regular pattern, while feet is irregular.
❎ Not quite. Find one noun that simply adds -s and one that changes its spelling completely.
Try it another way
Write the plural form of each noun.
Type the correct plural to complete each sentence.
✅ Exactly! Nouns ending in -x add -es in the plural.
❎ Not quite. Think about the ending needed after a noun that ends in -x.
✅ Exactly! Tooth forms its plural with a vowel change.
❎ Not quite. This noun is irregular and does not simply add -s.
✅ Exactly! A consonant before -y changes to -ies in the plural.
❎ Not quite. Change the -y before adding the ending.
Edit the sentence
Rewrite each sentence using the correct plural form.
Use the noun in brackets to complete the rewrite.
One mouse ran under the table. (rewrite for two, using: mice)
✅ Exactly! Mice is the irregular plural of mouse.
❎ Not quite. Begin with Two mice and keep the rest of the sentence.
The photo is on the shelf. (rewrite for more than one, using: photos)
✅ Exactly! Photo simply adds -s in the plural.
❎ Not quite. Change is to are and add -s to photo.
Her sister-in-law came to the wedding. (rewrite for two, using: sisters-in-law)
✅ Exactly! The plural ending attaches to the main word, sister.
❎ Not quite. Add the plural ending to sister, not to law.
Quick review
One form for one, another form for more than one.
Singular nouns name one person, place, thing or idea. Plural nouns name more than one.
Most plurals are formed by adding -s, or -es after -s, -ss, -sh, -ch, -x or -z.
A consonant before a final -y changes to -ies; a vowel before -y does not change.
Some nouns are irregular and form their plural with a vowel change, a different ending, or no change at all, such as man → men and sheep → sheep.
Some nouns are always plural in form, such as scissors. Others end in -s but are singular in meaning, such as news.
Compound nouns usually add the plural ending to their main word, as in passers-by.
Remember
Check the meaning before you check the ending.
A final -s usually signals a plural, but not always. Ask how many the noun refers to, then confirm whether the noun follows a regular pattern or must be learned as an irregular form.