1) How much...? is used with uncountable nouns.
- How much coffee do you drink?
- How much money do you have?
- How much fruit do you eat?
This expression is used when the quantity can't be countable. In the answer a countable noun must be used. For example, coffee, we drink cups of coffee. Cups are countable. For fruit, we eat pieces of fruit, or we can reply with the type of fruit, 3 apples, 2 bananas.
- How much coffee do you drink? I drink two cups of coffee.
- How much fruit do you eat? I eat three pieces of fruit.
- How much fruit do you eat? I eat four apples a day.
2) How many...? is used with plural countable nouns.
- How many apples are there in the fridge?
- How many sweets do you eat?
- How many hours does your baby usually sleep?
This expression is used for a quantity that can be represented by a number. In the answer we used the countable noun of the question.
- There are five apples.
- I eat ten sweets.
- He sleeps nine hours.
3) A lot of is used with countable and uncountable nouns for a big quantity.
- I drink a lot of coffee.
- I ate a lot of sweets.