|10 items or fewer. Because you can count items. Yeah! Fewer items from the Dollar Spot fell into my cart!|
Tarjay is not the singular culprit in this crime of the countables. Many a purveyor of goods have posted this sign in error above EXPRESS lanes. The Grammarian just happened to notice the friendly brand of the red bullseye had followed the crowd.
And the crowd, as the Grammarian notes, is not always right.
Here's how to know whether to use fewer or less:
Fewer should be used when one wants to describe a countable item. Fewer marbles. Fewer jet planes. Fewer everlasting gobstoppers.
The total countables = quantity.
Less should be used when one wants to describe a non-countable item. Something that would be difficult to measure by a standard metric. Less hope. Less courage. Less foaming at the mouth.
**The easy way to remember this is that many words that are non-countables are paired with the suffix "-less." Hopeless. Fearless. Restless.**