(Folks have already mentioned Odersky and Grossman for grokking functional programming) FutureLearn has an introductory Dutch course. I've only learned languag

(Folks have already mentioned Odersky and Grossman for grokking functional programming) FutureLearn has an introductory Dutch course. I've only learned languages from the Romance family previously, so it was a worthwhile experience. (Dutch-Australian in-laws) It's a taster course requiring further study but well worth satisfying your curiosity. Dutch (and Frisian) may provide a stepping stone to understanding Old English - there are recognisably 'Germanic' traits.