You can't. (If you bought the wrong language, too bad! Although you probably downloaded the game cause it is kind of hard to buy the wrong language!) Tut tut.
Chat with our AI personalities
No. You can't change languages. Even in SoulSilver.
Stickers? no stickers no avla your language
You can't, as with all traded Pokemon, you can't change their name.
man in violet city Pokemon center
no you can trade soulsilver pokemon to black