Gray said in an interview that Cotillard’s Polish accent seemed initially like one of the film’s most daunting challenges, and, nervous about its authenticity, he asked the Polish actress who plays Cotillard’s aunt in the film how accurate the accent was. The actress said that Cotillard had a pretty good Polish accent, but said that it sounded vaguely German. To which Cotillard responded: “I know, my character is from Silesia, which is between Germany and Poland, I’m doing it on purpose.”
Any more questions?
via World of Wonder