Question: When do we use fewer and when do we use less?

Fewer is the comparative form of few, and less is the comparative of little:

• Few, fewer, the fewest

• Little, less, the least

Few is used with count nouns, and little is used with non-count nouns. For example:

• I have few books.

• There are fewer cars on the road these days.

• There is very little water left.

• He pays less attention to his homework than basketball.