A Royal Affair

Swedish actress Alicia Vikander had to learn Danish. Vikander spent two months in Copenhagen in Denmark learning Danish prior to principal photography.

While all of the characters all speak Danish in the film, the court language in Denmark at the time was German. In real life neither Graf Bernstorff nor Johann Struensee spoke any Danish, and it is probable that Christian and Caroline also conversed in German rather than the "people's language." However, this is a movie made for a Danish audience. "Translating" the characters' speech to the language of the audience is in the same principle as Hollywood movies where Egyptian Pharaohs and Roman Emperors speak English.