If I were you?? If someone goes speaking in that manner, it isn't a coplete,neither a correct sentence. But if the individual goes like "if I were the boy,I wouldn't........ . The person's making sense....
If I was you-: simply means the person was present/there when the incident or anything he wants to say took place....for example "if I was you, I would have collected the money....this is more correct...THINK TWICE after reading this. Follow me on twitter for more @abexklovac1..