It �s important to understand the difference betweennoncount and count nouns when using many and much. Noncount nouns are often used to describe large categories while count nouns are usually more specific.

Examples:

• There is a car in the street. (singular count noun)

• Question: How many cars are in the street?
• Answer: There are a few cars in the street (plural count noun)

• Question: How much traffic is there?
• Answer: There is a lot of traffic. (noncount noun)

Noncount nouns always use a singular verb. Count nouns are singular or plural.

Much and Many are usually used with the negative:

Examples:

• There aren �t many students in the classroom. (perhaps 4 or 5 students)
• There isn �t much food in the refrigerator. ( a small amount of food)

Much and Many are usually not used in the affirmative:

Examples:

• There are many apples in the basket. It sounds better to say...
• There are a lot of apples in the basket.

• There is much milk in the refrigerator. It sounds better to say...
• There is a lot of milk in the refrigerator.

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.