About the "difference" I need to know which one is correct as below: 1) There are many differences between....... 2) There is not much difference between.... 3) There is much difference between.... ( or maybe it is better with " so much difference") The word "difference" is a countable noun as well as uncountable noun, right? I also have problem to define which is countable noun and which is not... how to figure them out?