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.
Less is used for uncountable, usually abstract nouns: money, happiness, snow, idealism.
Less is also used with adjectives and adverbs:
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.