When we want to show that something belongs to somebody or something, we usually add an apostrophe + s ('s ) to a singular noun and an apostrophe (' ) to a plural noun, for example:
- the boy's ball (one boy)
- the boys' ball (two or more boys)
Notice that the number of balls does not matter. The structure is influenced by the possessor and not the possessed.
| one ball | more than one ball | |
|---|---|---|
| one boy | the boy's ball | the boy's balls |
| more than one boy | the boys' ball | the boys' balls |
The structure can be used for a whole phrase:
- the man next door's mother (the mother of the man next door)
- the Queen of England's poodles (the poodles of the Queen of England)
Although we can use of to show possession, it is more usual to use possessive 's . The following phrases have the same meaning, but #2 is more usual and natural:
- the boyfriend of my sister
- my sister's boyfriend
Proper Nouns (Names)
We very often use possessive 's with names:
- This is Mary's car.
- Where is Ram's telephone?
- Who took Anthony's pen?
- I like Tara's hair.
When a name ends in s , we usually treat it like any other singular noun, and add 's:
- This is Charles's chair.
But it is possible (especially with older, classical names) to just add the apostrophe ':
- Who was Jesus' father?
Irregular Plurals
Some nouns have irregular plural forms without s (man → men). To show possession, we usually add 's to the plural form of these nouns:
| singular noun | plural noun |
|---|---|
| my child's dog | my children's dog |
| the man's work | the men's work |
| the mouse's cage | the mice's cage |
| a person's clothes | people's clothes |
sources : Original Link