7. Apostrophe (')

An apostrophe is a punctuation mark (') used to indicate possession or omission

Possession

Possession of singular nouns

To show possession of a single noun, the apostrophe + s is added to the following:

Examples:

noun that end in –s : actress's role; princess's lover; rhinoceros's skin.
noun or name : uncle's pipe; George's girlfriend; dog's tail; Thomas's car.
person's office or shop : I'll buy the pork at the Friendly Butcher's. / I'll be visiting Tom's.
only after the second name to show joint ownership : Jack and Jill's pail; Bonnie and Clyde's
both names to indicate separate ownership : Jack’s and Jill’s cars.

Possession of plural nouns

To show possession of a plural noun, the apostrophe + s is added to the following:

Examples:

plural nouns (owners) that end in –s : boys' bicycles; friends' houses; books' covers.
plural nouns (owners) that do not end in –s : children's toys; women's clothes; men's boots.
plural of abbreviations : many Dr.'s; many M.D.'s; many Ph.D.'s.
plural of a letter : Your p's, and c's are too big. / You must dot your i's and cross your t's.
plural of word or phrase : There are too many I’s and "you know’s" in his speech.

Omission

An apostrophe � + s is used to show letters or numbers that have been left out.

Omission of letters

Examples:

Using apostrophe to contract words : I'm = I am; we’re = we are; don’t = do not; can’t = cannot: rock ’n’ roll = rock and roll.
Using ‘s for is and has : he’s = he is/he has; it’s = it is/it has.
Using ’d for had and would : they’d = they had/they would; she’d = she had/she would.

In short answers, we can omit the noun if it is not necessary to repeat it.

Examples:

Is that your coat?
No, it’s Sandra’s.

Where is Tom?
He's at Noble Hardware's with dad.

Omission of numbers.

Examples:

To show plural of a number:

Your 5's are like the S.

To show that a number has been left out:

My grandfather died in '86.
My grandfather died in 1986.

To show the plural of a number that has been left out:

The uprising happened in the '60's.
The uprising happened in the 1960's.

Apostrophe + s used with singular noun.

Examples:

To show time : The workers took an hour’s break for lunch.
To show time : The library is just fifteen minutes’ walk from my house.
To show day : Why do you give me yesterday’s newspaper when it should be today's.
To show week : We will be away on a week’s trip to the uninhabited island.
To have double apostrophes : We were at James’ (or James’s) father’s office when he called.

Apostrophe + s used with compound noun.

Examples:

No : My mother's-in-law waistline is expanding fast.
Yes : My mother-in-law's waistline is expanding fast.

When apostrophe + s is not used to show possession

So far the noun or nouns to which the apostrophe + s is added to show possession has/have been living things. For non-living things, the apostrophe + s is not used. Instead, of the is used to show something is part of a non-living thing. The reason for this is that unlike living things, non-living things cannot own things.

Examples:

No : Your car's windscreen wipers need to be replaced.
Yes : The windscreen wipers of your car need to be replaced.

No : The air was black from the factory's smoking chimney .
Yes : The air was black from the smoking chimneys of the factory.

No : Look, the shovel's handle � must be held like this.
Yes : Look, the handle of the shovel must be held like this.