Apostrophes are used for 2 things:
- When words are joined together: you’re (you are), haven’t (have not), it’s (it is), Bob’s (Bob is/has), I’ll (I will)
- ‘This music’s great’(this music is great)
- ‘Tess’s got a new car’ (Tess has got a new car)
- ‘Sam’s left for the day’ (Sam has left for the day)
- To demonstrate possession (something belonging to something else):
- ‘Those are Jane’s shoes.’
- ‘That dog’s coat is really shiny’
- ‘Men’s, women’s and children’s clothing’ (see note on plurals below)
The frustrating exception
The exception to the possessive apostrophe rule is its – there is only an apostrophe if you mean to say ‘it is’ (i.e. two words joined together). There is no apostrophe when it is possessive.
The title of this article is a good example of both forms:
It’s (it is) not its (the apostrophe’s) fault it’s (it is) complicated.
There are a few examples where apostrophes are frequently used when they’re not needed, left out when they are, or put in the wrong place!
Numbers and decades
Nearly always, there is no apostrophe. It was the 1990s, the 80s.
- ‘In the 1990s, Apple was a struggling brand.’
- ‘There are 100s if not 1000s of books in the shop.’
A good way to remember this is to think of writing out the numbers in full – you wouldn’t use an apostrophe then either:
- ‘In the nineteen nineties, Apple was a struggling brand.’
- ‘There are hundreds if not thousands of books in the shop.’
There’s no apostrophe if you just mean ‘more than one’:
- ‘There were 200 MPs at the conference.’
- ‘CDs and DVDs have been replaced by media streaming services.’
If you mean something belongs to the acronym, you should add an apostrophe:
- ‘The CEO’s strategic plan is inspired.’ (The strategic plan belongs to the CEO)
If you are joining a word to the acronym, you also need an apostrophe. But in most cases it is clearer just to write the sentence in full:
- ‘The DVD’s scratched.’ (The DVD is scratched)
- ‘The CFO’s compiled a report.’ (The CFO has compiled a report)
Plurals – before the ‘s’ or after it?
Often mistakes are made when you want to demonstrate something belonging to a plural.
If the plural ends in ‘s’ the apostrophe is after it:
- ‘The kids’ hands were filthy.’ (This refers to more than one child, if you wrote ‘The kid’s hands were filthy,’ you would mean just one child)
- ‘The ladies’ club is being renovated’
If the plural doesn’t end in ‘s’, the apostrophe is before it:
- ‘The men’s locker room is empty.’ (men is plural, you cannot have one men and two mens. Same goes for women and children).
- ‘People’s decision not to vaccinate is selfish.’
Expressions of time
OK, I admit this one’s a little tricky. Time periods are treated as possessive:
- ‘In two weeks’ time we leave for Spain.’
- ‘That will be an hour’s work.’
- ‘I need to give a week’s notice to cancel the appointment.’
- ‘It costs more than a year’s salary.’
Plural forms of time (days, weeks, months etc) are generally accepted with or without the apostrophe, so you can err on the side of caution and leave them out.
For singular time periods, saying it out loud helps. If you say an ‘s’ at the end it will need an apostrophe, otherwise it would be spelt incorrectly:
- ‘He needs a week’s holiday.’ (You can’t have ‘a weeks’ and you wouldn’t say ‘a week holiday’)
- ‘Last year’s campaign was a great success.’ (last year is singular so you can’t write ‘last years,’ nor would you say ‘last year campaign’)
By Gina Velde