* ActorAllusion: The French lieutenant compliments his German counterpart on his excellent French compared to his poor German. The German lieutenant responds "but your wife is not German." Guillaume Canet, the actor who played the French lieutenant, was married to the German actress (and a co-star in the film) DianeKruger at this time.
* FakeNationality: Danish singer Anna Sørensen was portrayed by German actress DianeKruger.
** Who was married at this time to French actor Guillaume Canet, who played the French lieutenant in the film. This provides occasion for an ActorAllusion 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.
* NonSingingVoice: Nikolaus and Anna's performances are dubbed over by two opera singers.
* TheCastShowOff: 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.