The words fewer and less are commonly confused in English, or rather, less is used while fewer tends to fall by the wayside. You’ll be less confused and make fewer mistakes after reading through this lesson.
Fewer is used with countable nouns: people, animals, chairs, shoes.
You know fewer people than I do.
There should be fewer books on the table.
I have fewer ideas than everyone else.
Fewer of us show up each year.
Less is used for uncountable, usually abstract nouns: money, happiness, snow, idealism.
I hope less snow falls this year.
We need more money and less debt.
I have less computer savvy than you.
You should spend less of your time complaining.
Less is also used with adjectives and adverbs:
I’m less happy than I used to be.
He runs less quickly than you.
The Bottom Line
Less is the more common word, there’s no doubt about it. But many speakers seem to use it all the time, even in the relatively fewer constructions that need fewer. Just remember that if the noun can be preceded by a number (one person, three dogs, six of us, nineteen problems), it should be modified with fewer. Otherwise, less is best.