The rule is: the word 'it's' (with apostrophe) stands for 'it is' or 'it has'. If the word does not stand for 'it is' or 'it has' then what you require is 'its'. This is extremely easy to grasp. Getting your itses mixed up is the greatest solecism in the world of punctuation. No matter that you have a PhD and have read all of Henry James twice. If you still persist in writing, 'Good food at it's best', you deserve to be struck by lightning, hacked up on the spot and buried in an unmarked grave.

The reason it's worth standing up for punctuation is not that it's an arbitrary system of notation known only to an over-sensitive elite who have attacks of the vapours when they see it misapplied. The reason to stand up for punctuation is that without it there is no reliable way of communicating meaning.

Writers and painters alike are in the business of consulting their own imaginations, and stimulating the imaginations of others. Together, and separately, they celebrate the absolute mystery of otherness.

If you still persist in writing, "Good food at it's best", you deserve to be struck by lightning, hacked up on the spot and buried in an unmarked grave.

Well, start waving and yelling, because it is the so-called Oxford comma and it is a lot more dangerous than its exclusive, ivory-tower moniker might suggest. There are people who embrace the Oxford comma and people who don't, and I'll just say this: never get between these people when drink has been taken. Oh, the Oxford comma. Here, in case you don't know what it is yet, is the perennial example, as espoused by Harold Ross: "The flag is red, white, and blue." So what do you think of it? Are you for or against it? Do you hover in between?

The rule is: the word 'it's' (with apostrophe) stands for 'it is' or 'it has'. If the word does not stand for 'it is' or 'it has' then what you require is 'its'. This is extremely easy to grasp. Getting your itses mixed up is the greatest solecism in the world of punctuation. No matter that you have a PhD and have read all of Henry James twice. If you still persist in writing, 'Good food at it's best', you deserve to be struck by lightning, hacked up on the spot and buried in an unmarked grave.

Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves.