If you've got a DVD, read the back of the DVD, like read the kind of little plot summary. Wikipedia pages for films and shows have really detailed information. Maybe you can go onto a website like IMDB, which is the internet movie database. Just get some background info before you kind of jump in. I would say that if they start watching it and they don't enjoy it and they stop watching and they feel a bit bad about their English then that would consider that to be a failure.