Actually I don't think that it really makes much of a difference which "dialekt" one learns. I've noticed up here that the dialect changes from valley to valley. I you can learn any dialect it can mean a substantial plus to your intergration in this nation. Trying to learn is probably more important than learning (yes they will laugh). I converse in a mix of Züri/Aargau/Bärnertütsch. Up to now I only have one friend in Prättigau that I don't understand. I work with a ungerengadiener and converse with him just find. My tip is just go for it and try to stay away from english conversationists

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Cheers Mal