Less or Fewer

Although the conventional wisdom is that fewer is used for countable things and less is used for non-countable things (sometimes called mass nouns), I am starting to suspect it's a little more complex than that.

The rule seems to work well when specific numbers are not involved:

Less sugar, but fewer sugar lumps
Less hair, but fewer hairs
Less happiness, but fewer happy moments
Less shopping in the basket, but fewer items

But in mathematics we always use less than:

68 is less than 86
The symbol < means less than

Also we seem to use less than when we are talking about measured quantities – for example, time, distance and speed:

The bell rang for less than 10 seconds
Windsor is less than 30 miles from London
I was travelling at less than 40 miles per hour

Although seconds, miles and miles-per-hour are countable, we say we are talking about non-countable time, distance and speed to explain our use of less, even though the words time, distance or speed don't appear in the sentences. I wonder, though, whether it's simply that we use less than when numbers are involved. So less than 10, less than 30 and less than 40 are the phrases which we mentally focus on, and which thus dictate the use of less than.

In that case it would be quite reasonable to say

I was buying less than 30 items

And so a checkout could feasibly be marked "This checkout for people buying less than 6 items", or "Less than 6 items" for short. If this is correct, can we then deny the variant "6 items or less" even though it doesn't include the mathematical phrase less than?

There is also the quite separate argument that just as I am going to Molly's is fine because there is an implied "house" on the end of the sentence, so 6 items or less is fine because there is an implied "shopping" on the end.

Whatever the rights and wrongs, I think it's fair to say that it is not clear-cut and that this often-cited "abuse" of English by supermarkets is not as obviously wrong as language pundits would have us believe.

Paul Doherty, 2004.