Are you making these mistakes when you use the apostrophe?

This may not sound like a very exciting topic, but one of the most common mistakes that I have to fix when proofreading texts for native speakers is incorrect use of the apostrophe. Therefore I decided to write a post about it to explain when it should be used and highlight some of the common errors.

When should you use an apostrophe?

1. to replace missing letters in words

Examples of this are don’t (do not), I’m (I am), he’s (he is). The apostrophe replaces the missing letter.

2. To show possession

This shows that something belongs to somebody. We can talk about Kirsty’s students, my mother’s car or my friend’s new coat. It doesn’t matter if we are talking about one or more things. It could be Kirsty’s student or Kirsty’s students. If the thing that belongs to someone is plural, the plural is made in the usual way.

I once knew a dog called Raffles. The rules are slightly different for names ending in an “s”, so I would talk about Raffles’ bed, not Raffles’s bed or Raffle’s bed. The same rules would apply to James’ bike or Nicholas’ jacket.

However this is a style issue and some people would advocate adding an ‘s to any singular word. Therefore you may also see James’s bike (but never Jame’s bike, unless the bike belongs to someone called Jame).

“S’” is also used to make plurals possessive.
My neighbour’s garden = the garden that belongs to my neighbour.
My neighbours’ garden = the garden that belongs to my neighbours.
My colleague’s office is the office belonging to my colleague.
My colleagues’ office is the office belonging to my colleagues.

I wrapped my friend’s Christmas presents = I am giving my friend more than one present.
I wrapped my friends’ Christmas presents = there are multiple Christmas presents and they are for more than one friend.

If two people possess one thing together, you need an apostrophe after the final name: Sarah and Robert’s house. If they have separate possessions, each person needs an apostrophe: Sarah’s and Robert’s passports were on the table. You can’t share your passport with someone because it only belongs to you. “Sarah and Robert’s bikes” is ok if they are a couple and they jointly own the bikes. You could also say “Sarah’s and Robert’s bikes”, if you want to emphasise that Sarah and Robert have their own bikes or that Sarah and Robert have nothing to do with each other and you’re just talking about their bikes in the same sentence.

What mistakes do people often make?

1. Using an apostrophe to replace a missing letter before punctuation

If the word with an apostrophe to show a replaced letter comes before a comma, full stop or other punctuation mark, you should write the sentence out in full. Don’t write things like:
I can’t believe how happy I’m. (It should be “I can’t believe how happy I am!”)

Are you going to the train station? If you’re, I’ll give you a lift. (It should be “if you are, I’ll give you a lift.”)

2. It’s or its? You’re or your?

It’s = it is. It’s raining.
Its = something that belongs to “it”. The dog wagged its tail.

Therefore you shouldn’t write things like “its cold today” or “it was winter and the tree had lost most of it’s leaves”.

Your = something that belongs to you.
You’re = you are.

Therefore you shouldn’t write “You’re brother came to see me yesterday” or “You don’t know what your talking about”.

3. Adding s’ to words that are already plural

Words like women, men and children are already plural. You can’t have one children or one women (because the singular versions are child and woman). Therefore it is not necessary to write “s’” after these words. The children’s toys (the toys belonging to all the children) were on the floor. The women’s changing rooms are that way.

4. Making plurals with an apostrophe

If you had a shop that sold vegetables, you could write a sign to say that you were selling potatoes, tomatoes and carrots (but not potato’s, tomato’s and carrot’s).

5. Don’t change the name of a company by putting the apostrophe in the wrong place

If I opened a shop called Major Chocolate Cakes, and I wanted to advertise my grand opening, it would be “Major Chocolate Cakes’ grand opening”. This isn’t because I’d be selling more than one chocolate cake, but because the name of the company can’t be changed. Saying “Major Chocolate Cake’s” would be changing the name of my shop. It needs to be treated like a name ending in “S”, as we did with James’ bike.

6. Forgetting the apostrophe

I’ve seen documents that talk about the customers requirements and the managers signature. The apostrophe had been forgotten altogether and even if the rest of the document is well-written, this doesn’t make a good impression.

Have you seen any mistakes that involved the apostrophe lately?

If you have, tell me about them in the comments section!

Find out more

This is where you can find out about my proofreading service. You can also get in touch with me or sign up for my monthly newsletter using my contact form.