Part of speech of "Much"

Question

(1)

I don't care too much about it.

In this sentence, 'much' is a 'pronoun' or an 'adverb'?

(2)

A situation or action is too much for you

In this sentence, 'much' is a 'pronoun' or an 'adjective'?

Answer 1

I don't care too much about it.

Too much answers the question "how X do I care?" "How" questions are adverbs (they qualify the sense of a verb).

A situation or action is too much for you

Much is a pronoun here. To be is a copular verb that can act as an "equal sign" for two nouns. Pronouns are able to take the place of nouns or stand in for where a noun would go but doesn't appear because the idea is indefinite.

Much is never an adjective. If you want to say there's a large amount of X, and X is a noun, use many instead.

There was much disappointment today.

There were many disappointing events today.

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You're right, much can be a determiner. Most determiners that don't also act as pronouns are never on the far end of a copular verb. For possessive pronouns (really determiners), there's special words for example.

This is my box.

This box is mine (if you said this box is my the listener/speaker will think the sentence is unfinished).

But if the determiner can also be a pronoun, then it's fine to put it after to be or other copular verb.

My box is this (works because this works as a determiner and pronoun).

There is much chaos.

The chaos is much.

It's far more common to use a qualifier like too or very with much after to be or other copular verb, but a plain much isn't wrong. It will sound a little jarring and is less common than using a qualifier with much.

The chaos is too much.

It seems a bit much.

The perfume doesn't smell very much.