1. We Use some in a positive context when don’t want to specify the number or quantity. ex : I have some money. / Let’s go have some fun.
2. Use many with countable nouns, when want to refer to a large but indefinite number. For that reason, some and many are not interchangeable, each meaning something different. ex : How many pieces of pie did you eat? / We have so many cousins!
3. We use any when it is negative as well as in most cases of questions. ex : I don’t have any money / We don’t have any Mangoes.