Some time back, we discussed the difference between “less” and “fewer.” Both of these terms refer to having a smaller quantity of something, but they cannot be used interchangeably. In similar manner, there is a difference between how you use “much” and “many.” These sound similar, but you cannot use them interchangeably.
Thankfully, the rules for choosing between “much” and “many” are very similar to the ones you’d use for choosing between “less” and “fewer.”
MUCH is used when modifying nouns (items, objects, people, etc.) that are typically uncountable or not typically counted. For instance, you could achieve much success in your life. It would not make sense to say that you have achieved three successes, because the noun “success” is not quantifiable.
MANY is used when modifying nouns that are countable. It would make sense to say that I review many gadgets as part of my freelance writing work. This is because it is possible to count the number of gadgets. It would not be appropriate to say that I review much gadgets.
It is not a matter of singulars and plurals, since both “much” and “many” are used to modify plural nouns. If you are having trouble understanding the difference between the two, remember the strategy that I described when discussing less and fewer. Put a number in front of the noun in question. If it makes sense with the number, use many. If it sounds wrong, use much. Three phones makes sense, so you could say many phones (and not much phones).
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