Nahuatl

Do the actors playing Aztecs speak Nahuatl in the film? I just recently saw it and really enjoyed the way they placed Malinche in the film, and having her speak what sounded like one of the indigenous languages. Just wondering if it was actually Nahuatl or not. It added a nice touch to the movie.

I was kind of shocked the director didn't have the Aztecs speaking Spanish, given that this is Hollywood and I expected it to be less historically accurate than it turned out to be.