When to use du and Sie « Eintauchen. A very much recommended article by Dale Askey or @daskey.
Reality is, that even I as a native German sometimes struggle with this. Reason: rules are not as straight anymore! People in media for example tend to use often the “du” although they never met before. This happens especially when people are in the same age group. And personally I find that quite refreshing. I must admit that I am sometimes even a bit annoyed by the continuous “Sie” and “Du” decision making. Reason is “little me” having have been spoiled with simplicity in that respect for almost 7 years now. The Brits and the Swedes simply do not have that problem. It seems only ze Germanz and the Frenchies are putting themselves in these awkward situations requiring a decision for Du or Sie, Vous or Tu… Mindboggling sometimes, really.
Another thing I like about Dale is that he chose to spend some time at my old university of applied sciences . Hope you have a great time, mate!
(P.S.: Even without knowing him, I would not hesitate saying “du” to Dale. But, hmmm, what if I was a student? Hmmm, it should be “Sie” then, shouldn’t it? Unless he invites me to say “du”. Well, and there we go again with all that “Schlamassel“.)