You use much to indicate the great intensity, extent, or degree of something such as an action, feeling, or change. Much is usually used with 'so', 'too', and 'very', and in negative clauses with this meaning.

If something does not happen much, it does not happen very often.

You use much in front of 'too' or comparative adjectives and adverbs in order to emphasize that there is a large amount of a particular quality.

If one thing is much the same as another thing, it is very similar to it.

You use much to indicate that you are referring to a large amount of a substance or thing.

You use much in expressions such as not much ,not very much, and too much when replying to questions about amounts.

If you do not see much of someone, you do not see them very often.

You use much in the expression how much to ask questions about amounts or degrees, and also in reported clauses and statements to give information about the amount or degree of something.

You use much in the expression as much when you are comparing amounts.

You use much as to introduce a fact which makes something else you have just said or will say rather surprising.

You use as much in expressions such as 'I thought as much' and 'I guessed as much' after you have just been told something and you want to say that you already believed or expected it to be true.

You use as much as before an amount to suggest that it is surprisingly large.

You use much less after a statement, often a negative one, to indicate that the statement is more true of the person, thing, or situation that you are going to mention next.

You say nothing much to refer to something that is not very interesting or important.

If you describe something as not much of a particular type of thing, you mean that it is small or of poor quality.

So much for is used to indicate that you have finished talking about a subject.

If you say so much for a particular thing, you mean that it has not been successful or helpful.

If you say that something is not so much one thing as another, you mean that it is more like the second thing than the first.

If you say that someone did not do so much as perform a particular action, you are emphasizing that they did not even do that, when you were expecting them to do more.

You use so much so to indicate that your previous statement is true to a very great extent, and therefore it has the result mentioned.

If a situation or action is too much for you, it is so difficult, tiring, or upsetting that you cannot cope with it.

You use very much to emphasize that someone or something has a lot of a particular quality, or that the description you are about to give is particularly accurate.