Help please!

[ej]

Why can I say 'a car' but not 'a water'?

Is it because water cannot be described in singular terms

Thank you

[Tdol]

If you are thinking of the liquid, then we don't think of it as having singular\plural- thye same is generally true of substances and materials. If we are buying a bottle of it, then we can ask for 'a water and a coffee',but here we are thinking about the bottles and cups.