deep_blue's answer is correct, but i'd like to add that we also use some in offers like: would you like some tea? we also use some in questions when we think the answer is yes like; is there still some juice in the fridge?

Both the words "some" and "any' are use for countable and uncountable nouns. Some means a few or a little. And any means none in negative sentences, and a few or a little in questions. Positive sentences: we use "some", Example: I have bought some bread. I have bought some apples. In negative sentences, we use any, In negative clauses, we use any. Note, however, that any alone is not a negative - it must be not ... any Example: I have not bought any bread. I have not bought any apples. In questions, we usually use any. Example: Have you bought any bread? Have you bought any apples?