The Genitive Case (or Possessive Case) is typical of the English Language through the use of an apostrophe (‘) followed or not by S . It is basically used to show that something belongs or is associated with someone or some element. The ‘S comes after the name of the possessor. Look:
The name of the girl is Lauren. The girl‘s name is Lauren.
The shoe that belongs to Cinderela – Cinderela‘s shoe.
The blouse that belongs to my friend – My friend‘s blouse.
The house that belongs to my grandchildren – My grandchildren‘s house.
The computers that belong to our parents – Our parents‘ computer.
Normally use ‘s for animals, people and places:
The cat’s food is expensive.
Daniel’s book is here.
Brazil’s beaches are beautiful.
Use ‘s with periods of time and time expressions:
John took a year’s course to become a teacher.
She lives far from here. It’s a day’s journey.
But for things, ideas, etc., usually use of:
The color of a house can change everything. (and NOT the house’s color)
The source of his illness is unknown. (and NOT the illness’s source)
First Name or Last Name ending in S you can add just ‘ or ‘s:
Mrs Williams‘ sons or Mrs Williams‘s sons.
When there is more than one noun possessing something in common add ‘s in the last noun:
Charles and Diana‘s wedding. (That means it’s both wedding).
When there are more than one noun possessing different things add ‘s in all nouns:
Joshua’s and Rose’s friends (That means Joshua’s friends are different from Rose’s friends).
How to make Possessive Nouns:
– singular nouns: + ‘s
My dad’s car
Jack and Daisy’s house
The dog’s mouth
My cousin’s store
The photographer’s camera
– most plural nouns + ‘
Those boys’ toys
The grandmothers’ stories
The thieves’ names
The dogs’ ears
The ladies’ hats
– plural without s: + ‘s
The men’s passports
The women’s clothes
The children’s parents
The postmen’s letters
The policemen’s guns
It’s possible to use more than one possessive noun.
My cousin has got a teacher. He has got a wife. = My cousin’s teacher’s wife.
Laura has got daughters. They have got toys. = Laura’s daughters’ toys.