Sure, it’s a small issue in the scheme of things, but it’s something that’s been bugging us lately. Shouldn’t a Rhodes Scholar know the difference between which and that? Isn’t the Prime Minister setting a bad example for schoolkids when he utters grammatically incorrect sentences, every day, on national television?

You might have noticed, too, that Tony Abbott has a “which” problem: he regularly uses which when he should use that.

The pedants among you will know that “which” takes a comma, and you use it in a non-restrictive clause, i.e. a clause where you are adding extra information, but you could understand the meaning of the sentence without it. “That” does not take a comma, and you use it when you are adding information that is crucial to the understanding of the sentence.

Here’s an example of correct usage:

“Tony Abbott chose to be photographed in front of a sexist sign about Australia’s first female prime minister. The stunt, which was deeply offensive, should have cost him his job.”

“Tony Abbott chose to be photographed in front of a sexist sign about Australia’s first female prime minister. Shouldn’t a stunt that was deeply offensive to 50% of voters have cost him his job?”

It’s time for Tony to ditch the which.