Well, these two words drive me crazy every time I try to chew the cud in order to draw a clear line between them. ANY and SOME. Please consider the following:
If you have any/some money, please let me know.
Do you know anyone/someone here?
If anyone/someone knocks at the door, what will you do?
If you talk to anyone/someone, stare into their eyes!
Which ones are right, guys? If there is a sentence in which those two are acceptable, please tell me the reason.