Apostrophe abuse appears to be a modern disease. One that threatens to turn into an epidemic. Quite why, Lord knows. Simple apostrophe usage is a doddle to understand.
There are two common instances where you use apostrophes. When something’s missing. And when something belongs to someone.
The omission example. You’ve already seen it.
When something’s missing. You’ve already seen it.
A compressed form of ‘When something is missing’ and ‘You have already seen it’.
That’s the easy one. Even autocorrect software on phones gets that right usually.
It’s the possession issue that tends to confuse people, which is why you see ‘it’s’ and ‘its’ used wrongly all the time, even on professional news web sites these days.
The whole issue is well explained here. Mostly people understand it when we see proper names involved. Few people would write, ‘Oh look at Michaels dog over there.’ We know it’s ‘Michael’s dog’. But the word ‘it’ is a lot more common which leads to a lot more confusion given that the possessive here does not involve an apostrophe. So you write ‘the dog ate its dinner’. Not ‘the dog ate it’s dinner’.
Again from those clever people in Oxford…
its (without an apostrophe) means ‘belonging to it’:
The dog wagged its tail.
Each case is judged on its own merits.
it’s (with an apostrophe) means ‘it is’ or ‘it has’:
It’s been a long day.
It’s cold outside.
It’s a comfortable car and it’s got some great gadgets.
I’m not a grammar Nazi but I do get annoyed by laziness. And really this is laziness — if you think about it, you can usually work out the correct usage.
Here, though, is one gotcha, a situation I always have to think about and check. What about people’s names that end in ‘s’. Do you use Thomas’s dog or Thomas’ dog?
Tough one and people do argue about it. I bow to the wisdom of the Oxford Dictionary people quoted in the link above here (and do please remember I’m talking about UK English — usage may be different across the Atlantic).
To quote the experts…
With personal names that end in -s: add an apostrophe plus s when you would naturally pronounce an extra s if you said the word out loud:
He joined Charles’s army in 1642.
Dickens’s novels provide a wonderful insight into Victorian England.
Thomas’s brother was injured in the accident.
With personal names that end in -s but are not spoken with an extra s: just add an apostrophe after the -s:
The court dismissed Bridges’ appeal.
Connors’ finest performance was in 1991.
Common sense really. Why write something in a way it would never be pronounced? Very pertinent to my current work in progress too since I have characters called ‘Vos’ and ‘Pijpers’. So it would be ‘Vos’s dog’ but ‘Pijpers’ cat’. Exactly how it would be pronounced.
Except I’m not sure I would say ‘Dickens’s’. I think Dickens’ might sound better.
That’s apostrophes for you. Always good for an argument.