There is one particularly frequent example if this: the BBC regularly confuse the words "deficit" and "debt" - a bugbear of mine, and something James Forsyth deals with in his column in this week's magazine.
Even when I blog about it, some CoffeeHousers say they don't know the difference. So Cameron should ban the word "deficit" and simply say "overspend" instead - for that is what it is. The public can instantly distinguish between reducing the annual overspend, and reducing the debt burden.
To win the argument, one must first break free from the terms of debate set by Gordon Brown. This means making clear the extent of Britain's fiscal peril. It should also mean never saying "deficit" again and, instead, calling government overspend by its name. This would be one small step to winning the massive argument Cameron will soon need to make on restoring fiscal sanity to Britain.