Quote Originally Posted by impulse View Post
I understand that but there must be a reason why Много takes genetive case.
I do not understand your concern. When learning another language, I would like to know "How is an expression constructed?" and not "Why is it so?".
To answer "why?" you have to go deep into the history of the language. Native speakers are usually unable to answer "why?", all what they can do for you is to show "how".

But actually I do not mind discussing "why's" for the reason of curiosity. However, it does not affect language learning.

Quote Originally Posted by impulse View Post
This adverb must be the genetive form of a word. Maybe it has the nominative, the accusative, dative etc equivalents?
Adverbs are unchangeable. The concept of case is not applicable to them! What you are asking here is a sort of grammar nonsense (don't take it personally).

Quote Originally Posted by impulse View Post
Like in English (if I am not mistaken) "lot" means "many of something". So it is used as "a lot of cars". My point is "a lot of" in English has a reason for the way it is used so Много must also have a reason.
I do not understand why you provide the example of "many of something" and you're still surprised that Russian works the same way with its "много + Genetive Plural"? You should not be surprized then.

If you say, "пять столов" (five tables), does it surprize you?
The same is if you say "количество столов" (a quantity of tables), множество столов (plenty of tables), сколько столов? (how many tables) etc. - quantities are expressed using the genitive (QUANTITY of SOMETHING in plural).
Много is just the same word as any of the listed above: много столов.

BTW, it is English which is illogical, cause sometimes it uses "of" and sometimes it skips it:
dozens of books, hundreds of books, thousands of books, a lot of books, a great number of books, quantity of books, but
five books, ten books, a hundred books, many books, how many books.

I would prefer using "of" everytime And that exactly corresponds the Russian genitive.