When speaking about the quantity of something, there are a variety of words that are often used, called quantifiers:
a lot of
Some of these apply only to countable nouns, while others apply only to uncountable nouns, and some apply to both types of nouns:
How these words are used depends on their context. SOME and ANY mean the same thing, but some is used for positive statements whereas any is used for negative statements and questions:
Do you have any milk and biscuits?
We don't have any biscuits but we have some milk.
MANY and FEW are used for countable nouns and many is used for a large quantity but few is used for a small quantity.
I have a few doubts and many questions.
Note: A FEW does not mean the same as FEW:
I have few friends = I have no friends.
I have a few friends = I have a small number of friends.
MUCH and LITTLE are used for uncountable nouns, and much is used for large quantities but little is used for small quantities.
I have little time and not much patience.
MUCH is only used for negative statements and questions. For positive sentences other words like A LOT OF, LOTS OF or PLENTY OF are used.
Note: A LITTLE does not mean the same as LITTLE:
I have little time = I have no time.
I have a little time = I have some time.