People often use the words less and fewer interchangeably, but they are not quite the same. Using the correct vocabulary makes your writing more sophisticated.
Do you know which of the following sentences is correct?
There were fewer people there than I expected.
There were less people there than I expected.
The first sentence is the correct one. People is a plural noun so we need to use the word fewer. Another way of looking at it is to decide whether the noun can be counted or not. People can be counted, so the correct word is fewer.
If something can't be counted or has no plural, then we use the word less.
You should eat less salt. (We talk about salt as one thing rather than counting the grains.)
My sister has less free time now she is studying. ('Free time' has no plural.)
In this worksheet you can practise choosing whether to use fewer or less in different sentences.