Student or Learner
"Iím not sure if we have [any / some ] extracopies in stock."
In this case, I understand "any" is fine, but is "some" wrong?
Yes, only 'any' would work here.
In this context, we'd only use 'some' to confirm. "Yes, I think we have some extra copies in stock."
Since the original sentence expects the answer to be negative, it uses 'any'.