Less and Fewer – Amount and Number
The way it was explained to me in school is this:
use less when you’re writing about something you can’t count like molasses.
I have less molasses than Joe on my beans.
Use fewer when you can count the items mentioned.
There were fewer people at the concert than expected.
NOT There were less people at the concert…and this we hear all the time!
Same principle when using amount.
DON’T SAY: A large amount of dancers twirled across the stage.
SAY: A large number of dancers, etc.