Spelling rules for regular plurals
The ending of the singular noun decides the spelling.
| Singular ends in | Rule | Examples |
|---|---|---|
| Most letters | Add -s | car, cars; idea, ideas |
| s, ss, sh, ch, x, z | Add -es | bus, buses; class, classes; dish, dishes; watch, watches; box, boxes |
| Consonant + y | Change y to -ies | city, cities; country, countries; baby, babies |
| Vowel + y | Add -s | day, days; key, keys; boy, boys |
| -f or -fe (some nouns) | Change to -ves | knife, knives; leaf, leaves; life, lives; half, halves |
| -f (other nouns) | Add -s | roof, roofs; chief, chiefs; belief, beliefs |
| -o (some nouns) | Add -es | potato, potatoes; tomato, tomatoes; hero, heroes |
| -o (other nouns) | Add -s | photo, photos; piano, pianos; radio, radios; video, videos |
Irregular plurals
These don't follow the spelling rules, so they have to be learned. Words from Latin and Greek are common in academic writing.
| Type | Singular and plural |
|---|---|
| Vowel change | man, men; woman, women; foot, feet; tooth, teeth; mouse, mice; goose, geese |
| -en ending | child, children; ox, oxen |
| Different word | person, people (persons in legal and formal notices) |
| No change | sheep, sheep; deer, deer; aircraft, aircraft; series, series; species, species; means, means |
| Latin and Greek | criterion, criteria; phenomenon, phenomena; analysis, analyses; crisis, crises; thesis, theses; curriculum, curricula (or curriculums) |
Nouns that are always plural, or look plural
Some nouns exist only in the plural and take a plural verb: trousers, jeans, scissors, glasses (for your eyes), clothes, goods, belongings. To count them, use a pair of or an item of: "two pairs of jeans".
Some nouns end in -s but are singular: news, mathematics, physics, economics. "Economics is a popular subject."
After one of, use a plural noun: "one of my friends", "one of the biggest cities". The verb agrees with one, so it is singular: "One of my friends lives in Pune."
Plurals in compound nouns and number phrases
In most compound nouns, the last word takes the plural: toothbrushes, bus stops, passwords. In some hyphenated ones, the main noun takes it: mothers-in-law, passers-by.
When a number and noun describe another noun, the noun stays singular and is usually hyphenated: "a ten-year-old girl", "a five-star hotel", "a 20-year period".
Common mistakes
Wrong: One of my friend lives in Canada.
Right: One of my friends lives in Canada.
One of is followed by a plural noun, and the verb agrees with one.
Wrong: There were many childrens in the park.
Right: There were many children in the park.
Children is already plural, so don't add -s.
Wrong: I need to buy a new trouser.
Right: I need to buy a new pair of trousers.
Trousers is always plural. Use a pair of to talk about one.
Wrong: We went on a three-days trip to Ooty.
Right: We went on a three-day trip to Ooty.
A number phrase before a noun works like an adjective, so the noun stays singular.
Wrong: The selection criterias are listed below.
Right: The selection criteria are listed below.
Criteria is already the plural of criterion.
Using this in IELTS and PTE
In IELTS Writing Task 1 you often write number phrases such as "a ten-year period" and "the number of households", where one form is singular and the other plural. In Task 2 and PTE Write Essay, academic plurals such as criteria, phenomena and analyses show range, but only if they are correct. Spelling errors in plurals, such as "countrys" or "potatos", count against accuracy in both tests.
5 questions
Exercise
Try each one, then open it to check your answer.
1. Write the plural: "wife"
wives
Wife is one of the -fe nouns that change to -ves.
2. Write the plural: "key"
keys
A vowel comes before y, so you just add -s.
3. Write the plural: "phenomenon"
phenomena
It is a Greek plural.
4. Is or are? "Physics ___ my favourite subject."
is
Physics ends in -s but is singular.
5. Correct this: "She stayed in a five-stars hotel."
She stayed in a five-star hotel.
Five-star describes the hotel, so star stays singular.
Frequently asked questions
Is it persons or people?+
People is the normal plural of person. Persons appears mainly in legal and official notices: "No more than six persons in the lift."
What is the plural of fish?+
Usually fish: "We caught three fish." Fishes is sometimes used when talking about different species.
Is news singular or plural?+
Singular. It ends in -s, but it is an uncountable noun: "The news is on at nine."
Why do we say a three-day trip and not three-days?+
When a number and a noun together describe another noun, they act like an adjective, and adjectives in English have no plural form.
Keep going
More grammar lessons
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