Who was married at this time to French actor Guillaume Canet, who played the French lieutenant in the film. This provides occasion for an Actor Allusion when the German lieutenant remarks "but your wife is not German" when his French counterpart compliments him on his excellent French.
Interestingly, while Kruger speaks fluent French, Canet does not speak German, like the French lieutenant he plays in the movie.
Non-Singing Voice: Nikolaus and Anna's performances are dubbed over by two opera singers.
The Cast Show Off: Multilingual skills of several actors, especially Daniel Bruhl (the German lieutenant) and Diane Kruger (Anna Sørenson), who switch back and forth between English, German, and French. Guillaume Canet (the French lieutenant) speaks only French and English and Alex Ferns (the Scottish lieutenant) sticks only to English, though.