Fewer? or less?

A few months ago there was a newspaper story about a major UK supermarket, which decided to change the signs above some of the tills because they had received so many complaints about grammar. The signs read, "10 items or less". The supermarket spokesman admitted no-one could agree whether the signs should say "less" or "fewer", so they simply avoided the issue and put up new signs reading, "about 10 items".

Unless you know the rules, choosing between "less" and "fewer" is hard.

There are many ways of explaining it, but Bill Bryson describes a simple rule of thumb in Bryson's Dictionary for Writers and Editors (Black Swan, 2008: 151): "Use less with singular nouns (less money, less sugar) and fewer with plural nouns (fewer houses, fewer cars)."

So one says "classes with fewer students", but "teachers set less homework".

This is a far easier way to explain the difference than the one I was taught, that "less" is used qualitatively and "fewer" quantitatively. This explanation does shed a little further light on the reason for the choice, though, and may appeal to the sense of humour of anyone who is interested in social sciences research methodology.

So now we know what the supermarket signs should have said. If anyone wants me to correct corporate signage in exchange for a trolleyful of groceries, do email!