"Much" can be used as a determiner, pronoun, or adverb. This is what I just found in Practical English Usage about adverbial much:
much as an adverb
We can use much as an adverb in questions and negative clauses.
- Do you work much at weekends?
- I don't travel much these days.
We can also use much before comparative adjectives and adverbs, in affirmative clauses as well as questions and negatives.
- She's much older than her brother.
- I don't drive much faster than you.
Much can be used before some verbs expressing enjoyment, preference and similar ideas, in affirmative clauses as well as questions and negatives, especially in a formal style.
- I much appreciate your help.
- We much prefer the country to the town.
- I didn't much enjoy the concert.
Very much can be used in affirmative clauses as an adverb, but not usually before a noun. Compare:
- I very much like your new hair style. (adverb)
- Thank you very much. (adverb)
- There is a whole lot of water coming under the door. (before noun)
(NOT There is very much water coming ....)
This entry is also relevant:
much or very with past participles
When a past participle is part of a passive verb, we can put much or very much before it, but not very.
- He's (very) much admired by his students. (NOT ... very admired ...)
- Britain's trade position has been (very) much weakened by inflation. (NOT ... very weekend ...)
When a past participle is used as an adjective, we usually prefer very. This is common with words referring to mental states, feelings and reactions.
- a very frightened animal (NOT a much frightened animal)
- a very shocked expression
- The children were very bored.
- She looked very surprised.
Common exceptions:
- That's Alice, unless I'm (very) much mistaken. (NOT very mistaken)
- He's well known in the art world. (NOT very known)
With amused, very and (very) much are both possible.
- I was very amused/much amused/very much amused by Miranda's performance.