Formation and uses of the possessive case
When the noun is singular, we make the possessive case by adding ’s to the singular.
Examples are given below.
The boy’s father
The girl’s mother
If the word ends in –s, only the apostrophe (’) is usually added.
For goodness’ sake
When the noun is plural and ends in –s, the possessive case is formed by adding only an apostrophe.
When the noun is plural but does not end in –s, the possessive case is formed by adding ’s.
When a sign or a title consists of several words, the possessive sign is attached to the last word.
The Sultan of Bijapur’s jewels
When two nouns are closely connected, the possessive is put only to the latter.
William and Mary’s reign
The possessive case is mainly used with the names of living things.
The Prime Minister’s bodyguards
The monkey’s paw
The possessive is also used with the names of personified objects.
At death’s door
The possessive is also with nouns denoting time, space or weight. Examples are:
In a year’s time
A week’s holiday
Five minutes’ walk
A pound’s weight
Some common phrases using the possessives are
At his fingers’ ends
For mercy’s sake
To his heart’s content
A boat’s crew
At his wit’s end
The possessive of a proper noun is often used to denote a building or place of business.
The memorial service was held at St. Paul’s.