Less vs. Fewer
In order to understand whether to use “less” or “fewer,” one must first understand the difference between count and non-count nouns:
A count noun is a noun which refers to things that exist as countable entities – you can point to these things and, theoretically, at least, count them. Boy, ocean, pen, house and Godiva truffles are all countable nouns:
“I saw the boy playing in the sandbox.” – how many boys? You can count them and say.
“I ate the Godiva truffles for lunch.” – how many truffles? Why, all of them, thank you very much!
Count nouns can be made plural and can exist either as a group – the truffles – or as a single entity – the boy.
A non-count noun is a noun which refers to things that can’t be counted, but which are things nonetheless. Weather, milk, snow, money, grass, and furniture are all examples of non-count nouns:
“The weather has been breezy and cold lately.”
“I prefer to make my hot cocoa with milk.”
Non-count nouns are not made plural – we don’t say things like “The weathers” or “the milks.”
Recognize that some words belong to both classes – “love” can refer to a person and, when it does, it becomes a countable noun that one can make plural; “I’ve had many loves in my life, but none like you” is an example of “love” behaving as a countable noun. “He took her love and handed her back a shattered heart” is an example”love” behaving like a non-count noun. Also understand that we can count glasses of milk or blades of grass, but not milk or grass themselves.
Quantifying the different types of nouns is where we run into problems with less and fewer.
When talking about a non-count noun, use less:
I wish we had less snow in February.
Susan had less money than Jack did, so he paid for lunch.
There seems to be less foliage on the trees this spring than last.
Use fewer when talking about countable nouns;
This check-out lane is for ten items or fewer.
The restaurant has fewer customers during dinner than they serve at lunch.
Because of budget cuts and staff reductions, the college accepted 2,000 fewer students this year.