Can you tell me what's the difference between "so much as" and "even"?

"So much as" is a comparative phrase. "Even" can be used in a number of idiomatic ways but literally and originally means "flat" or "without irregularities". It is more usual to use the phrase "as much as" when comparing two quantities. "So much as" is used only in very particular conditions. "So", in this context, is used to refer to something which has already been mentioned - something like 'this' and 'that' and 'thus': "The American gallon does not contain as much as the English gallon", "The pink dress is not as much as the blue one" (= "the blue dress is cheaper than the pink one"). When you are talking about countable things - ounces, dollars, people, houses etc. - you should use "as many as": "The American gallon contains 128 fluid ounces; not as many as the English gallon, which contains 160 fluid ounces." "There are not as many people in a village as there are in a town." If you can give examples of where you are confused between 'so/as much as' and 'even', it would help.