Nothing whips grammar purists into a frothing frenzy more than supposed errors in the use of “less” and “fewer.” The rule is pretty simple: use “less” with non-count nouns: less sugar; use “fewer: with count nouns: fewer cups of sugar.
But little complications crop up. One can have many countable problems—who doesn’t?—but suppose one of your many countable problems is an aging cat that’s costing you a bundle of money in vet bills, and the cat suddenly dies. Would you sigh with relief, wipe away a tear, and say, “Well, at least that’s one fewer problem”? Of course not, at least not if English is your native language. Cats are as countable as sheep, but would you say “Of all potential pets, I like cats the fewest”?
Certain expressions with less involving count nouns are quite idiomatic: We have less than five miles to go before we come to a market that doesn’t have the grammatically incorrect “Ten Items or Less” sign at the express line. Write an essay on the less/fewer distinction in 25 words or less.
The “Ten Items or Less” sign at the supermarket has been sneered at and derided, I suspect mostly by people who buy organic carrots. The tender sensibilities of educated if confused elites notwithstanding, “10 Items or Less” is not an outrageous grammatical error at all. “Less” is quite natural with units of measurement: less than ten dollars to my name, less than 10 miles to go, and less than ten items in my grocery cart. Reversing the order, one keeps “less”: ten dollars or less, 10 miles or less, 10 items or less.
The small market in the village not far from us has been bullied into changing the express line sign to “Ten Items or Fewer,” but the large supermarkets have all steadfastly kept the “Ten Items or Less” sign. The large supermarkets probably have access to better grammatical advice and are pretty sure that the use of “less” in the sign will not confuse shoppers about just how many items they can take to the express line.
According to Merriam-Webster’s Dictionary of English Usage, less and fewer were used pretty much interchangeably until 1770, when the grammarian Robert Baker opined that “fewer” would be “not only more elegant … but more strictly proper” than “less” in a phrase like “no less than a hundred.” Why the opinion of a single grammarian had such influence is a mystery.
By now the distinction is so entrenched that most of us who paid much attention in school find phrases like “less people” very grating. There is nothing wrong with observing the grammar rules of Standard English as long as we realize that they’re arbitrary conventions and not commandments written in stone by some grammar deity. Some rules, like the one about not splitting infinitives or not beginning a sentence with a conjunction, are entirely bogus. Others, like the less/fewer distinction seem to drive ordinarily moderate people into a frenzied excess of hyper correction.