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It's neither South Africa nor the UK, though I'm surprised how often the native speakers of this particular language are mistaken for South Africans, given that I can think of hardly any salient connections between the two🙂
The correct answer is:
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Polish. Thanks for your guesses and congratulations to all those who were close or even hit the nail on the head, even if somewhat hesitantingly.
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A fair guess, but no :)
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An interesting and well-argued guess, but I’m afraid it’s nonetheless somewhat off the mark.
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Slavic is a good guess
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Your deduction is correct. They are Polish.
I suppose that's a pretty solid indication that they learned it well 🙂
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One of your picks is correct
They both initially moved to England for university - him at 19 and her at 21.
That's right, none of them is a native speaker of English - their English is learned via the standard combination of school, extracurricular courses, media exposure, and other typical means available in largely monolingual countries, and subsequently polished up abroad (at least two of them moved to Anglophone countries for university). Thus, I figured that the undercurrent of their native pronunciation should be sufficiently conspicuous to allow for making some educated guesses about their origin 🙂
„Then 3 hit me with surprise rhoticity and now I’m confused.” Hopefully at that point the challenge became entertaining 🙂