Countable and non-countable nouns

The last either/or way to classify nouns is into countable and non-countable.
  • Countable nouns (sometimes called unit nouns) are, as you might guess, nouns that we can count.
  • Non-countable nouns (sometimes called mass nouns) are nouns that we can't count.
So what do we mean exactly by "nouns that we can count"? There's a very easy way to demonstrate this. Let's take the noun apple and see what happens when we start to count apples:
1 apple
2 apples
3 apples
This seems to make sense - we can count apples in this way. But does it work with all nouns? Let's take another one, water, and find out.
1 water
2 waters
3 waters
This sounds a little strange - it doesn't seem like we can count water in the same way that we can count apples. So what's the difference between apples and water that lets us count one but not the other? Well, the difference is that we can't easily divide water up into individual units in order to count it. To do this we'd have to do something like put it into glasses, or think of it in drops:
1 glass of water
2 glasses of water
3 glasses of water
1 drop of water
2 drops of water
3 drops of water
Now it sounds better - but that's because we're counting glasses or drops of water and not water itself. Here are some more examples of countable and non-countable nouns. Try counting each of them and see if you agree with our classification:
chair coffee
castle weather
friend traffic
screen English
baby information

Countable, non-countable, singular and plural

Now, let's think back to the last section where we talked about singular and plural nouns. Can we make any sort of relationship between countable/non-countable and singular/plural nouns?

If we think about it, being able to count a noun must mean that we can have more than one of it (2 apples, 3 chairs). This means that countable nouns can be either singular or plural. But if we can't count something, this means that we can't make it plural. As we've seen, it makes no sense to add "s" to water and say "2 waters". So non-countable nouns can't be made plural. And that's why in the last section we said that most nouns can be made plural, not all nouns.

Nouns which are both countable and non-countable

Some nouns can be both countable and non-countable, depending on how we're using them. Have a look at these sentences:

I go to work every day.
The works of Van Gogh are astonishing.
In the first sentence "work" is a concept that we can't count. But in the second sentence we're using the noun "works" to mean individual paintings, which we can count. So in the second sentence "work" is countable. Here's another example:
I like sandwiches with cheese and lettuce.
Many different cheeses are made in the UK.
The same thing applies here. In the second sentence we're using "cheese" to mean individual types of cheese which, again, we can count. So unlike all our other classifications, which were very clear-cut, here we have to think a little more about how we're using the noun before deciding how to classify it.