Its and It's

Use 'its' to show ownership and 'it's' to mean 'it is' or 'it has'.

This pair surprises many readers because the apostrophe works opposite to what you might expect. 'It's' with an apostrophe always means 'it is' or 'it has'. 'Its' without an apostrophe shows ownership: the dog wagged its tail. Why no apostrophe for ownership? Think of 'his' and 'hers': they show ownership with no apostrophe, and 'its' belongs to that same family. Test it the same way as before.

'It's raining, and the bird is shaking its wings. ' Expand the first: 'It is raining' works, so 'it's' is right. Expand the second: 'shaking it is wings' does not work, so 'its' is right.

• 1it's = it is or it has.
• 2its = belongs to it (like his and hers, no apostrophe).
• 3Expand to 'it is' to test.