Overview
Possessive nouns use an apostrophe + s ('s) or just an apostrophe (s') to show that something belongs to someone, or that there is a close relationship between two nouns. This is called the genitive or possessive case.
1. Singular Nouns — Add 's
To show possession with a singular noun, always add 's.
| Owner (singular) | Possessive form | Example |
|---|---|---|
| the cat | the cat's | the cat's tail |
| David | David's | David's book |
| the teacher | the teacher's | the teacher's desk |
| the company | the company's | the company's policy |
| a child | a child's | a child's toy |
- Anna's car is red.
- I borrowed my friend's pen.
- The doctor's appointment is at three.
2. Plural Nouns Ending in -s — Add ' (apostrophe only)
When the plural already ends in -s, just add an apostrophe after the -s.
| Owner (plural -s) | Possessive form | Example |
|---|---|---|
| the teachers | the teachers' | the teachers' meeting |
| the students | the students' | the students' books |
| the cats | the cats' | the cats' food |
| the parents | the parents' | the parents' decision |
- This is the students' common room.
- The parents' evening is on Friday.
3. Irregular Plurals (Not Ending in -s) — Add 's
Irregular plural nouns that do not end in -s take 's like singular nouns.
| Owner (irregular plural) | Possessive form | Example |
|---|---|---|
| the children | the children's | the children's playground |
| the men | the men's | the men's room |
| the women | the women's | the women's team |
| the people | the people's | the people's choice |
4. Names Ending in -s
For names ending in -s, both forms are acceptable in modern English, though 's is more common in speech.
| Name | Possessive | Example |
|---|---|---|
| James | James's (preferred) or James' | James's car |
| Thomas | Thomas's or Thomas' | Thomas's report |
| Keats | Keats's or Keats' | Keats' poetry |
5. Joint Possession vs. Separate Possession
| Type | Rule | Example |
|---|---|---|
| Joint possession (shared) | Apostrophe on last name only | Tom and Anna's flat (they share it) |
| Separate possession | Apostrophe on each name | Tom's and Anna's flats (separate flats) |
6. Possessive 's vs. "of" Construction
Both express possession, but there are preferences:
| Prefer 's | Prefer "of" | Example |
|---|---|---|
| People / animals | Things / inanimate objects | the president's speech |
| the roof of the building (not the building's roof — less natural) | ||
| Short, common phrases | Long or complex nouns | the car's engine is fine; the engine of the car also works |
| Time expressions | — | yesterday's news, a week's holiday |
7. Common Mistakes
| Mistake | Correction | Explanation |
|---|---|---|
| The cats's food | The cat's food | Only one apostrophe-s |
| The students's books | The students' books | Plural ending in -s → apostrophe only |
| The childrens' toys | The children's toys | Irregular plural → add 's |
| Anna' bag | Anna's bag | Missing -s after apostrophe |
| The car it's engine | The car's engine | No "it's" for possession; use 's |
8. Real-World Examples
- Shakespeare's plays are studied all over the world.
- The women's football team won the championship.
- I stayed at my parents' house last weekend.
- The children's laughter filled the room.
- That is today's newspaper — have you read it?
Summary
| Owner type | Rule | Example |
|---|---|---|
| Singular noun | Add 's | dog's, teacher's |
| Plural noun (ends in -s) | Add ' only | dogs', teachers' |
| Irregular plural | Add 's | children's, men's |
| Names ending in -s | Add 's (preferred) | James's |
| Joint possession | 's on last name | Tom and Anna's |
| Time expression | Add 's | yesterday's, a week's |