I have to admit that I am biased toward supermarkets.  I don’t drive, so it’s awfully convenient to have most all of the food products I regularly consume under a single roof. Furthermore, the variety in the average supermarket is a fascinating testament to the opulence of our modern society — the Ralphs nearest my apartment stocks no fewer than 15 types of canned pastas, including my dear ABCs and 123s, a meal that I find both educational and nostalgic.  Such benefits allow me to overlook the flaws in the supermarket system.

Others are less willing to cut supermarkets such slack. Oddly, though, instead of concerning themselves with real supermarket problems, like the preponderance of Whitney Houston songs on the PAs, they’re obsessed with the check-out line:

Alas, it’s not merely fictional superheroes who are interested in the name of the express lane, but real live people.  Both in defense of my friends the supermarkets and for the sake of my sanity, which wears ever thinner every time bad prescriptivism goes unchallenged, let me explain why “10 items or less” is acceptable.

Here’s the claim that agitated prescriptivists stake: less is restricted to uncountable items, and fewer is restricted to countable items. (Uncountable, or mass, items are those like milk, money, mortar; countable items are those like coins, cups, kitties.)  That is why an Ideal Boy says things like:

(1a) You need to drink less pop and more milk.
(1b) You need to eat fewer sweets and more brussels sprouts.

(Statements like these are the reason that an Ideal Boy has few friends.)  Now, what’s interesting about this is that swapping less for fewer is not too bad, while using fewer for less sounds quite terrible, at least to me:

(2a) *You need to drink fewer soda.
(2b) You need to eat less sweets.

My intuition is borne out on the Internet:

Google hits for less X fewer X
Y stuff 369,000 516
Y objects 17,200 27,100

So the idea that fewer is limited to countable items is pretty well borne out by usage.  However, we can see that less is less stringently affiliated with uncountables.  (Language Log has even more data on this.)  So is this a sign of that horror of horrors, the destruction of the English language by modern speakers who can’t be bothered to learn the rules of the grammar?

Unsurprisingly, no.  As it turns out, this whole notion that fewer is countable and less is uncountable has been traced back to 1770 by the Merriam-Webster Dictionary of English Usage.  And it wasn’t a rule back then, but rather a preference of a single author, Robert Baker.  (That’s not to say that no one agreed with him, only that no one else seems to have put it in print back then.)  So it’s not that modern ne’er-do-wells are ruining the language; at worst, they’re returning it to an earlier state.  The OED attests countable less in 1481, derived from an Old English usage attested by no less a personage than King Alfred.

All right.  So less used to be fine with countables.  Then a dude came along and said he wasn’t fond of that, and his opinion eventually got codified into a rule.  But, as MWDEU and the Google results point out, countable less remains common, despite the widespread acceptance of this rule outlawing it.  Now, to me, that suggests that the rule that less can’t be used with count nouns is spurious.

You’re welcome to disagree; you may be of the opinion that the fact that a large proportion of the populace believes this rule exists makes it exist.  (It’s like the principle of common usage, but in reverse.)  That’s a (sort of) reasonable stance, but I don’t think that accepting this rule rules out 10 items or less.

Countability is gradient.  Arnold Zwicky has written extensively on this issue on Language Log.  In different situations, the same noun can be countable or uncountable.  Anecdotally, I sometimes say “I got some email” (uncountable) while at other times I say “I got some emails” (countable).  But also, in some situations, it can be unclear whether a usage is countable or uncountable.  For example, let’s say you want to discuss the calamitous effect that the current economic downturn has had on your salary:

(3a) I’m making four thousand dollars less than last year.
(3b) ?I’m making four thousand dollars fewer than last year.

Dollars sure looks like countable here, modified as it is by a number and a plural suffix.  But I don’t think anyone’s going to argue (3b) is better than (3a) — unless they’ve drunk an awful lot of Robert Baker’s Kool-Aid.  Why’s that?  Probably because we’re not thinking of the individual dollars in the $4000, but rather as the money as a mass.  The MWDEU mentions that this same situation holds for a variety of seemingly countable nouns, such as distance, units of time, and statistics.  Now let’s return to the or less/fewer construction, for these sorts of nouns:

(4a) Having trimmed my caloric intake, I now eat seven pounds or less of avocados each day.
(4b) ?Having trimmed my caloric intake, I now eat seven pounds or fewer of avocados each day.

Again, I prefer the less sentence to the fewer sentence. That means that a seemingly countable noun can take or less if it can be thought of as a mass or as a single unit.  That’s why 10 items or less can be acceptable.  Clearly the objects being taken into the checkout can be thought of as a mass noun — namely, groceries.  You can say I bought some groceries, but you can’t say I bought a grocery, unless you mean you’ve bought a store.  Because groceries are commonly regarded as a mass, it’s not really weird to say “10 items or less”, and not much weirder than saying “10 pounds or less” or “10 gallons or less”.

Finally, it turns out that “X items or less” was actually quite commonplace before the grocery stores started using it.  For instance, in Google Books, there are 13 full-text hits for “items or less” before 1950.  (To be fair, some of them are repetitions of a legal phrase, but there’s still a few unique hits.)  Take a guess how many full-text hits there are for “items or fewer” before 1950.  Now, check your guess.  Pretty damning, eh?

Summary: The idea that less can’t be used with count nouns isn’t well supported; it’s a rule that hasn’t ever been strictly followed, especially for count nouns that can be perceived as masses.  Groceries lend themselves to perception as a mass, so it’s no surprise that “10 items or less” is favored now, just as it has been historically.  Please stop complaining about this.