Or it could be a typo (as in man-made) My guess is that they only use Youtube videos that already have subtitles in the target language. But I'm curious to kno

Or it could be a typo (as in man-made) My guess is that they only use Youtube videos that already have subtitles in the target language. But I'm curious to know how exactly they've built their database of videos/transcripts. I wonder if they curate the videos manually at all.