USING THE APOSTROPHE.
WHO’S TO KNOW WHETHER IT’S A SITUATION WHICH REQUIRES APOSTROPHES?
Should it be WHO’S or WHOSE?
Should it be IT’S or ITS?
Should it be APOSTROPHES or APOSTROPHES’ or APOSTROPHE’S?
And, by the way, should it be REQUIRE’S?
When used correctly, apostrophes indicate one of two things:
1. Possession
2. Abbreviation
They should never be used to show a plural. Never.
1. Possession These can be sub-divided into two major situations.
a) When the thing or person which possesses something else is singular.
b) When there are several things or people which possess something.

a) Singular possessor or owner (only nouns, not pronouns. For pronouns, see below )
The child’s toy (The toy which the child owns)
My aunt’s house (The house which my aunt possesses)
The book’s cover (The cover which the book possesses)
b) Plural possessor or owner. (These can also be sub-divided.)
i. When the plural possessor or owner is made plural with an “s”.
ii. When the plural possessor or owner is made plural in an irregular way.

i. Plural made by adding “s” at the end of the singular word
The books’ covers (the covers of – or possessed by – the books)
The walls’ surfaces (the surfaces of the walls)
My credit cards’ limits (the limits of my credit cards)
The girls’ team (the team owned by the girls)
ii. Plural formed in irregular manner
The children’s noise
The men’s complaints
The women’s image
The people’s welfare

BUT, DO NOT USE AN APOSTROPHE for these forms of POSSESSION
Where the possessor is his/hers/its/ours/yours/theirs
This book is hers
This book is his
This car is ours
This house is yours
Of all the suggestions, I prefer theirs
Its effect was felt over a large area.
2. Abbreviation
There are two main types of abbreviation
a) Pronoun + part of the verb To Be or the verb To Have
I’m
I’ll
I’ve
I’d
We’re
We’ll
We’re
You’re (This is a tricky one; NOT TO BE CONFUSED with YOUR!)
You’ll
You’ve
You’d
He’s/ She’s
He’d/She’d
He’ll/ She’ll
Let’s
b) Part of verb To Be or verb To Have + “not”
Isn’t
Aren’t
Hasn’t
Haven’t
Hadn’t
Couldn’t
Shouldn’t
Wouldn’t
Mightn’t
Won’t
Can’t

BACK TO THE PROHIBITION: DON’T TRY TO MAKE PLURALS BY ADDING APOSTROPHES.
The danger mainly lies with words where the singular ends in a vowel, especially an “O”, (tomato – tomatoes, not tomato’s and not tomatos’; potato – potatoes, soprano – sopranos. But let’s add apostrophe – apostrophes, not apostrophe’s and not apostrophes’.) Because of the common error of greengrocers’ signs advertising “tomato’s”, this is often referred to as the “greengrocer’s apostrophe”. However, many greengrocers use apostrophes (not apostrophe’s!) impeccably and, sadly, many more non-greengrocers become horribly tangled up in their uncertainty about the apostrophe’s correct use.