2.- UNCOUNTABLE NOUNS:

Uncountable nouns are substances, concepts etc that cannot be divided into separate elements. We cannot count them. For example, we cannot count "water". We can count "bottles of water " or "litres of water ".

We usually treat uncountable nouns as singular. We use a singular verb.

For example: Your luggage is very heavy

We cannot use the indefinite article a/an with uncountable nouns. It's not possible to say "a music". But we can use a + container + of + uncountable noun: a bottle of milk, a can of coke, a piece of information, a loaf of bread, an article of clothing, a jar of perfume, etc.
Uncountable nouns can be modified with the following quantifiers:

a) SOME (Affirmative sentences), ANY (Negative and Interrogative sentences):

Examples: a) I have got some money b) There isn't any rice left

b) A LOT OF (Affirmative sentences), MUCH (Negative and Interrogative sentences):

Examples: a) There is a lot of wine in this bottle b) We don't have much information

c) LITTLE (Negative meaning), A LITTLE (Positive meaning):

Examples: a) I have got little free time b) We have got a little money