We say it the original correct way in the US. Other countries changed it for some reason. The guy that discovered it in 1808, Sir Humphrey Davy named it "Alumium" which based on Alumen (Latin for bitter salt)but quickly changed it to "Aluminum". I swear I remember reading that he kept getting shit on by the science community and his friends for naming a metal "bitter salt" in Latin ... but can't find a reference.
His colleagues in Britain did mess with him and start using the name "Aluminium" ... exactly because it ended in "ium" like ALL the other elements (Oxygenium, Carbonium, Ironium, Zincium, Nitrogenium, and the like). They US just kept the name the discoverer wanted instead of giving into those British asshats that just wanted to troll Sir Davy.
He also isolated Magnesium and named it "magnium", but later changed to magnesium. The guy just couldnt settle on names. Again, in my version of reality it is because his friends kept giving him shit.