'The Wanton Countess'

An aspect of the film actor is how they go about learning other languages. I've searched and searched for stories about Robert De Niro learning Sicilian for The Godfather II or whether it was something he had already known growing up in an Italian home (which was not the case).

So, how the heck did Farley Granger, an American actor, learn Italian so well and so (seemingly) fluently  to pull off playing an Austrian officer in The Wanton Countess?

Then I learned that it was overdubbed with an Italian voice-over guy. Then, why did they even cast Granger in the first place? Granted, he had had success in Alfred Hitchcock's Strangers on a Train and Rope, but it was an Italian film, released in the United States almost as an afterthought. Co-star Alida Valli's career had hit a bump after controversy after the death of another actress connected her to nefarious happenings.

Granger's casting is a mystery. But it's good to know he didn't speak Italian on a whim.