Once you understand the difference between ‘less’ and ‘fewer’, it’s hard to mistakenly use one in place of the other. Saying ‘fewer puppies’ or ‘less water’ simply feels right, while talking about ‘less dollars’ or ‘fewer lumber’ just feels wrong, like putting your left shoe on your right foot.
Here’s the basic rule for choosing the right word: ‘fewer’ typically applies to individual things you can count – like puppies, ice-cream cones and limousines – while ‘less’ is used with things that don’t come in discrete, countable packages – like dog food, ice cream and petrol.
It’s not always an easy distinction to explain, though, especially not when so many people have become accustomed to hearing those words used incorrectly on a fairly regular basis. Not just in casual, day-to-day conversations either but in magazine articles, news broadcasts, television commercials and other places.
On the Grammar Girl podcast a while ago, for instance, readers bemoaned usage errors such as ‘15 items or less’ signs in grocery stores, ‘five people or less’ signs on library (!) conference-room doors and ‘50 per cent less sugars’ in ketchup ads. However, while recommending more careful word choices in such cases, Grammar Girl writer Mignon Fogarty acknowledged the less-vs-fewer divide hasn’t always been clear-cut. In fact, she noted, King Alfred the Great, the “great promoter of English over Latin,” actually wrote about “less words” in 888.
There is also a grey area between the realms of ‘less’ and ‘fewer’, a space where the choice becomes a little less obvious. You tend to encounter this with words describing time, ages, distances or amounts of money.
Consider these examples from the Oxford Dictionaries blog:
‘A person with a score of less than 100 will have difficulty obtaining credit.’
‘Heath Square is less than four miles away from Dublin city centre.’
“Wait,” you might be saying. “A score is countable, right? And so are miles. So why ‘less’ instead of ‘fewer’?”
Here’s Oxford’s explanation: “We use less in such cases because we’re actually still referring to total amounts (of time, money, distance, etc.) rather than individual units.”
So, yes, there are times when the whole less-vs-fewer issue is less than clear. Still, choosing the right word becomes easier with practice, checking and time, hopefully leading to fewer headaches for you in the long run.