多少杯水用how many 还是how much

how much water is in the cup?

how many cups of water are xxxx

how many 修饰可数名词; how much修饰不可数名词
多少杯水,杯为量词,可数的,所以用how many 修饰
水为不可数名词,用how much修饰

杯是可数名词,所以用how many 例如:How many bottles of water?(有多少杯水?)
如果直接问多少水,就用how much 了 例如:How much water are there in the bottle?(杯里有多少水?)

用how many ，how much 是多少钱的意思

how many 修饰可数名词; how much修饰不可数名词.

how much 用于不可数名词的提问