This is one of the most common mistakes we see in students’ writing – and it’s so easy to get right if you follow this simple rule.

If you’re shortening ‘it is’ or ‘it has’, use it’s.

If you’re not, use its.

That’s all there is to it.

So:

The dog sat on its tail. No apostrophe, as its isn’t short for ‘it is’ or ‘it has’.

It’s been a long day. Apostrophe in it’s as this is short for ‘it has’.

Got it?

Good!

Now put yourself to the test by clicking here.

When your results are emailed, print them off and pop them in to your class files.