​Possessives

Singular nouns

The boy’s uniform is blue.

Plural nouns 

The boys’ uniforms are blue.

The official Christian church calendar is a table containing the holy days, saints' days and festivals of the church.

One thing in possession

The girl and boy’s computer is on the table.

Each has their own possession: The girl’s and boy’s computers are on the table.

Irregular plural

Women’s high-heeled shoes are out of fashion.

This is the ladies’ cloakroom, and that is gentlemen’s

Nouns with more than one word

The Minister of Foreign Trade's speech at the peace talks made a deep influence on everybody.

Don’t take my pen, take someone else’s pen.

Mother in law’s hat is torn.

It is not my pen, it’s somebody else’s.

Proper nouns

Look at this picture of Picasso’s.

London’s attractions are fascinating.

Louis XVI's execution in January 1793 was followed by Robespierre's Reign of Terror.

I came into the Smiths’ cottage.

Compound nouns

The governor-general’s wife was wearing a plain white dress with a string of pearls that cost more than my two years' salary.

NB! Classical names ending in -s usually add only the apostrophe:

Pythagoras’ Theorem

Archimedes’ Law

Sophocles’ plays

Other names and nouns ending in - s can take 's or the apostrophe alone:

Mr Jones's (or Mr Jones' house)

Yeats's (or Yeats') poems

Duchess’ lunch or duchess’s lunch

Carlos’ stylebook or Carlos’s stylebook

for appearance’ sake or for appearance’s sake

for conscience’ sake or for conscience’s sake

for goodness’ sake or for goodness’ sake

Nouns plural in form, singular in meaning ending in -s take the apostrophe alone:

the series’ actors

the Academy of Motion Picture

Arts and Sciences’ history

In time expressions

a week's holiday

today's paper

tomorrow's weather

in two years' time

ten minutes' break

a ten-minute break

two hours' delay (a two-hour delay are also possible).

NB! No possession for inanimate ‘possessors'

the walls of the town

the roof of the church

the keys of the car

or

the town walls

the church roof

the car keys