The original film is in several languages depending on where it was released, but the US version was in English when I saw it in 1977 (and Joan Bennett has a line that is often quoted - but to do so here would spoil things for those who've never seen the film). However, the newly discovered 35MM print is in Italian so I believe what will be shown in theaters will be in Italian and I would suspect it's pretty much a certainty that it will have English subtitles...