Use fewer for things you can count one by one — fewer books, fewer people, fewer mistakes. Use less for things you measure as a mass or amount — less water, less money, less time. The fastest test: if you can put a number in front of the noun and make it plural (three books), choose fewer; if you can't (three waters doesn't work), choose less.
Fewer and less are both comparatives meaning "a smaller quantity," but they belong to different kinds of nouns. Fewer is the comparative of few and pairs with countable nouns — nouns with a plural form that you can number individually: one email, two emails, ten emails. Less is the comparative of little and pairs with uncountable (mass) nouns — things measured as an undivided whole, with no natural plural: water, sand, money, traffic, information, furniture.
A reliable shortcut is the many/much test. If the noun takes many, it takes fewer (many emails → fewer emails). If it takes much, it takes less (much traffic → less traffic). Put simply, fewer answers how many? and less answers how much?
People, mistakes, cars, bugs, and followers can all be counted and pluralised, so fewer is correct. Swapping in less is the classic error:
Time, salt, money, traffic, and caffeine are all mass nouns, so less is right. Using fewer here sounds wrong to native ears: ✗ fewer traffic, ✗ fewer information, ✗ fewer advice.
Watch for nouns that switch sides depending on meaning. Coffee is a mass noun as a drink you pour (less coffee) but countable as servings (two coffees, please → fewer coffees). The same goes for wine, cheese, and experience. Let the meaning decide: are you measuring a substance or counting units? A parallel pair follows the same split — use amount with mass nouns (the amount of work) and number with countables (the number of tasks).
Here is where the tidy rule bends. When a number refers to a measurement of time, money, distance, or weight, standard English uses less — even though the unit looks countable. The reason is that the amount is treated as a single quantity, not as separate items you would tally.
Say less than three hours, not fewer than three hours — you mean one stretch of time, not three tickable hours. The same logic covers ages (children less than five years old), temperatures, and percentages (less than 20 percent). Two fixed idioms also take less no matter what: one less and no less than. We say "That's one less thing to worry about," not "one fewer thing" — even though thing is countable. One less is simply the idiomatic form.
What about a countable noun straight after less than — is it less than 100 people or fewer than 100 people? In careful, formal writing, choose fewer, because people are countable: fewer than 100 people applied. But less than 100 people is common in speech and print, and many usage guides accept it when the number acts as a rough threshold rather than an exact headcount. It is a soft preference, not a hard error — so use fewer in an essay or report, while less won't raise eyebrows in conversation.
Strictly, yes. Items are countable, so a purist would write 10 items or fewer. The or less version is so widespread that it now reads as idiomatic, but it remains a favourite target of language sticklers. In 2008, the British supermarket Tesco sidestepped the argument entirely, changing its express-lane signs to the neutral "Up to 10 items" on the advice of the Plain English Campaign. If you want to be unimpeachable, write fewer; if you are painting a shop sign, up to 10 items keeps everyone happy.
Match the comparative to its base word. You would say a few apples (not a little apples), so it is fewer apples. You would say a little water (not a few water), so it is less water. In short: few → fewer, little → less. Then remember the measurement escape hatch — money, time, distance, and weight take "less."
Partly, it is a modern invention — and honesty matters here. Using less with countable nouns is not new sloppiness; it goes back over a thousand years, to the Old English of King Alfred the Great, and appears throughout respected literature. The idea that less is wrong before count nouns began as one writer's preference: in his 1770 book Reflections on the English Language, grammarian Robert Baker remarked that "No Fewer than a Hundred" struck him as "more elegant" and "more strictly proper" than "No less than a Hundred." He framed it modestly — "I should think," "appears to me" — as personal taste, not law. Later grammarians hardened that suggestion into the rule we teach today.
So what should you do? Follow the distinction in formal writing — editors, examiners, and style guides expect it, and fewer mistakes genuinely reads as more polished than less mistakes. But know that less with countables is not a grammatical crime; it is a usage preference with a long, respectable history on the other side.
This is one of the rare usage points where American and British English fully agree: the rule, the exceptions, and the measurement carve-outs are identical on both sides of the Atlantic. The only real difference is cultural — the "items or less" supermarket row has been fought most loudly in Britain. Whichever English you write, the guidance is the same: fewer for what you count, less for what you measure, and less for money, time, distance, and weight.
In careful writing, say fewer people. People are countable — one person, fifty people — so the count-noun word fewer is correct: fewer than 100 people applied. Less people is common in casual speech and won't confuse anyone, but fewer people is the polished, correct choice for essays, reports, and anything formal.
It depends on what the number counts. For a measurement of time, money, distance, or weight, use less: less than 20 minutes, less than $20. For separate countable items, use fewer: fewer than 20 chairs. The test is whether the number names a single amount (less) or a tally of individual things (fewer).
Strictly, no — items are countable, so the precise form is 10 items or fewer. That said, 'or less' is so common it now reads as idiomatic. Some supermarkets, including Tesco, dodged the debate in 2008 by switching signs to 'up to 10 items.' Use fewer if you want to be unimpeachable.
Because money is treated as a measured amount, not a stack of countable dollars. When a number refers to money, time, distance, or weight, English uses less: less than $100, less than three hours, less than five miles. You are describing one quantity, not counting separate items, so fewer would sound wrong.
Not historically. Less has been used with countable nouns for over a thousand years, and the 'rule' began as one grammarian's personal preference in 1770. In modern formal writing, though, editors and examiners expect the fewer/less distinction, so following it still makes your writing look more polished and precise.
