Much, many, a lot of

Much, many, a lot:

"Much", "many", and "a lot of" indicate a large quantity of something, for example "I have a lot of friends " means I have a large quantity of friends.
Much, many, and a lot are quantifiers.

Study the examples below:

How much money have you got?	I haven't got much money.
	I have got a lot.
	I have got a lot of money.
How many students are in the classroom?	There aren't many.
	There are a lot.
	There are a lot of/lots of students.

In the interrogative forms we use:

• much with uncountable nouns. (money, bread, water...)
  Example:
  How much money/bread/water...is there?
• many with countable nouns. (students, desks, windows...)
  Example:
  How many students/teachers/desks... are there?

In the negative forms we use:

• much with uncountable nouns. (money, bread, water...)
  Example:
  I haven't got much money/bread/water...
• many with countable nouns. (students, desks, windows...)
  Example:
  There aren't many students/teachers/desks...

In the affirmative forms:

In spoken English and informal writing we tend to use:

• a lot, a lot of, lots of with countable and uncountable nouns.
  Example:
  "How many students are there in the classroom?"
  "There are a lot."
  "How many students are there in the classroom?"
  "There are a lot of / lots of students"..

In formal written English:

• It is also possible (and preferable) to use many and much rather than a lot of, lots of and a lot in formal written English.
  Example:
  There are many students.
  Much time was spent on studying.

So if you're speaking or writing to friends (informal), use a lot, a lot of, lots of. But if you want to be more formal, perhaps it is preferable to use much and many.

Exercise 1
Exercise 2