Expansions that don't support my language?

[shirpu]

My The Sims 3, Pets, Nightlife, Supernatural and World Adventures are installed from CD and are in finnish. My friend wants to buy few exspansion keys for me, but they will not support finnish language, because they are bought outside EU and all that jazz....

Can I still use them from Origin and they won't mess up my whole game because of invalid language support or should I just re-install my CD games and change language to english?