fewer vs. less
Supermarket express lanes have been quietly teaching this wrong for fifty years. "Ten items or less" is on thousands of signs, and it is the single most cited example of an error in English. The complication is that the people doing the citing are on shakier ground than they think.
fewer
Used with plural count nouns — things you could number individually.
- Fewer applicants met the criteria this year.
- We had fewer objections than expected.
- There are fewer than twenty seats left.
- Fewer people, not less people — the one the supermarket sign gets wrong.
less
Used with mass nouns — quantities measured rather than counted. Also with time, money and distance, even though those are countable.
- We have less time than the schedule suggests.
- This version uses less paper.
- It cost less than five hundred dollars.
- The drive is less than ten miles. (Countable miles, but distance takes "less" — one of the genuine exceptions.)
Why fewer and less get mixed up
The traditional rule is about counting. Fewer goes with things you can count one by one: fewer emails, fewer people, fewer mistakes. Less goes with things you measure as an amount: less water, less time, less noise.
The rule bends in a few settled places. Money, time, distance and weight are usually treated as amounts even when written with numbers: less than ten dollars, less than an hour, less than five miles. "One less" is standard for a single item: one less thing to worry about. And percentages follow whatever they are a percentage of.
A quick check: if you can put a number directly in front of the noun (three emails), use fewer. If you can't (three waters sounds wrong), use less.
Common mistakes
There were less people at the launch than we expected.
✓There were fewer people at the launch than we expected.
People can be counted one by one, so fewer.
The new process uses fewer paper.
✓The new process uses less paper.
Paper here is an amount, not a count, so less.
We had less complaints this month.
✓We had fewer complaints this month.
Complaints are countable: three complaints, so fewer.
Quick way to remember
Ask whether you would count the thing or measure it. Count it, use "fewer." Measure it, use "less." Then remember the three exceptions — time, money, distance — which take "less" regardless: less than an hour, less than fifty dollars, less than a mile.
Questions
Is "10 items or less" wrong?
By the traditional rule, "10 items or fewer" is correct, and some stores have changed their signs. "Or less" is common enough as a fixed phrase that most readers won't notice, but fewer is the safer choice in careful writing.
Is it "less than 50 miles" or "fewer than 50 miles"?
Less than. Distances, like money and time, are treated as a single amount rather than a set of separate miles.