You probably remember your English teacher telling you to use fewer for things you can count (“fewer apples”) and less for things you can’t count (“less money”).
I heard it from a beloved English teacher in high school, and I just assumed that ’twas ever thus. He knew everything and was always right – or so I thought.
Not true! Using less with countable nouns (“less apples”) goes all the way back to Alfred the Great in 888, according to the Oxford English Dictionary. The rule I learned from my English teacher didn’t come along until the 18th century – and then it was only a suggestion, not a rule.
Old habits die hard, and that’s as true of English as any other habit. People have been saying “less apples” for more than a thousand years. That usage isn’t going away any time soon!
But I’m going to warn you against a usage that’s becoming more common: “fewer than one.” No. It’s “less than one.” Please!