Many vs Much - Which one should be used?

Question

"There's so many people in here!"

"There's so much people here!"

Which one should be used, and why?

Answer 1

If you can count it and it doesn't designate a category, use "many".

If you cannot count it or it designates a category, use "much"

I have many friends.
I have much to offer.
There are many ways to get it wrong.
It doesn't make much sense.

Answer 2

Many is used in enumerated quantities. If it can be counted in individual items, use many. If the quantity cannot be counted, use much.

"There are so many people in here!"

"There is so much I still need to learn!"

Answer 3

Simple rule of thumb: if the following word is plural use many, otherwise much

"I don't have much time"

"I don't have many books"

"how much money do you have?"

"how many cars can you see?"

Answer 4

"There's so many people in here!"

"There's so much people here!"

There's = There is

There are so many people in here! The problem found is b/c of the usage of are vs. is. You would use are because the subject [people] is plural.