So what's the difference between countable and uncountable nouns?
Let's take a look at two nouns: cars and water. If you stand outside you will proabably see cars passing. You can count these cars 1 car, 2 cars, 3 cars and so on.
Water, however, can not be seperated and counted. We do not say 1 water, 2 waters.
So now we know that cars are countable and water is uncountable.
When we want to count water we have to say, for example, 'a bottle/glass of water' or '1 litre of water'.
Now take a look at the nouns in these ten sentences and decide if they are countable or uncountable.