The quickest way to lose friends and make your coworkers loathe you is by correcting someone’s grammar. But what is the frustrated pedant to do when she hears “I had less candy than my brother, but my dad still took some of mine.” and she knows, knows, that a terrible grammatical sin has been committed?
The answer is, of course, to secretly judge them and let a happy little smile be the only outward signal of your intellectual, and frankly, moral superiority show.
The matter at hand is less versus fewer. As the rule says, fewer is for countable nouns and less is for uncountable ones, generally speaking. But, just because a noun can be plural, do not automatically assume that it should take the determiner fewer. Consider this passage from the New York Times:
Also use less with a number that describes a quantity considered as a single bulk amount: The police recovered less than $1,500; It happened less than five years ago; The recipe calls for less than two cups of sugar.
Also consider that certain phrases are idiomatic and therefore, acceptable. One such example would be “Write an paragraph is 200 words or less.” Linguist and author Stephen Pinker suggests that the less-fewer rule is applied by many pedants a little too forcefully. It’s acceptable to use less, he says, “with a singular count noun, as in ‘one less car’ and ‘one less thing to worry about’.” The ‘rule’ about less-fewer is one he considers “dubious” though a fair guide in terms of style.