[quote=rusty4297]
... Wouldn't you learn both names at the same time? *raises an eyebrow, seeing as they're technically the same zanpakuto, even if it's two separate swords*
[/quote]

Not in Aizen's case, as both Zanpakutos are individual. It's all made obvious in his history.

But if this isn't acceptable, then I already know how he'll learn both names.