Countable and Uncountable nouns

Countable nouns are nouns which can be counted.
one plate, two cars, six tables

Uncountable nouns cannot be counted. They aren't used with the indefinite article (a/an), they don't have a plural and they are used with a singular verb form.
Can you get some water?
A lot of damage was done to the monument.
The following nouns are usually uncountable: graffiti, weather, luggage, furniture, travel, knowledge, work, English, information, damage, research, homework, advice, progress, health, news.

Nouns which are both countable and uncountable.
- Many words for drink and food can be used both countably and uncountably.
I've made a cake. (C)
Can I have some more cake? (U)
- A word used countably may have a very different meaning from its countable version.
I would like a single room for two nights. (C) (=hotel room)
There's no more room on this bus. (U) (=space)

Making uncountable nouns countable.
- Some uncountable nouns have countable equivalents with similar meanings.
My job involves a lot of business travel. (U)
I have to make a lot of business trips. (C)
- Some other uncountable nouns can be made countable by using piece/s of or item/s of.
Let me give you a piece of advice.
- Certain other expressions are used with words for drink and food: a corton of milk, a spoonful of salt, a loaf of bread.

Others
- Words used with countable nouns: a/an, few, a few, many, a large number of, each, every, several.
- Words used with uncountable nouns: little, a little, much, a great deal of.
- Words used with countable and uncountable nouns: some, any, a lot of, lots of, no, all, plenty of, most.

Little and Few
These two words have more negative meanings. They mean "not much/many" or "not as much/many as desired/expected".
Sue has made little progess since the beginning of the week.
There were very few people at the stadium. 

A little and A few
These have more positive meanings. They mean "some" or "more than expected".
I have still got a few eggs. Enough to make an omelette.

Plenty of
This means "a lot of" or "more than enough".
Do not hurry. We have got plenty of time.