Every once in a while, I hear about how Darth Vader's name translates to "Darth Father", so those who spoke a foreign language had a clue that he was someone's father.
One high profile example of this is Pitch Perfect, where a character who had never seen The Empire Strikes Back predicts the twist ending:
Beca: [Movie endings] are so predictable, like, the guy gets the girl, and that kid sees dead people, and Darth Vader is Luke's father.
Jesse: Oh, right, so you just happened to guess the biggest cinematic reveal in history?
Beca: "Vader" in German means "father". His name is literally "Darth Father".
Jesse: Huh.
Personally, I think that Beca is full of it because "Vader" is a Dutch word, not German (although "Vater" is).
But it did raise the question: prior to the release of The Empire Strikes Back, did anybody actually predict that Vader is Luke's father? Or is this just a case of Monday morning quarterbacking?
Native dutch speaker here. When I was young I figured it out and the twist was meaningless to me, it was annoyingly obvious (given the desired impact of the twist). Granted: this happened many years after the film came out, and the twist was common pop-culture knowledge, but as far as I can remember I had no idea myself, Star Wars was just an old tape I had and at 5 or 6 I watched it and the name lended itself to giving it away (who knows whether I was influenced by general popculture though, just giving my anecdotal evidence).
– Ghoti and Chips Nov 05 '16 at 19:07