Hello Judy, In the sentence that you gave, you can't change "any" to "some." Here are the rules for using them both. Both "some" and "any" can be used to show an indefinite quantity or number. There are some differences in their usage. 1) "Some" is most common in affirmative sentences. "Any" is common in questions and negative sentences. I want some milk. (NOT I want any milk.) Is there any milk in the fridge? I haven't got any milk in the fridge. (NOT I haven't got some milk in the fridge.) 2) We use "some" in questions if we expect the other person to answer "yes" or if we want to encourage them to say "yes." Have you brought some paper and pens? (The speaker expects that the hearer has brought them.) Could I have some sugar, please? 3) If you use "any" in an affirmative sentence, it comes after words with a negative and limiting meaning like "never," "without," or "little." You never give me any help. We got there without any trouble. Source: Practical English Usage by Michael Swan I hope that this helps. Christine

Tough ask. To an English speaker, it sounds wrong or ambiguous. You could say, 'some kind of difference', 'some type of difference', 'some discernable difference', but they would still not convey the same meaning as 'any'. "Any" in this context means, 'none at all'. Other synonyms might be, "the least difference", "the slightest difference", "the minutest of difference", or possibly "the barest of differences". "Some" is not really used in a context where the absence of something is referred to or implied. "There isn't any doubt" means certainty. "There is some doubt" means uncertainty You would never hear, "There is any doubt." You would never hear, "There isn't some doubt." Hopefully, this helps.

1) some + plural Any + singular (use any for questions) 2) The most important difference is: . . . . . . . . . . . . Some has 4 letters but any has 3 letters.