Alternately a "cosmopolitan" city like Berlin and Copenhagen could work. Most of the locals speak English, and there are so many foreigners that English is hear

Alternately a "cosmopolitan" city like Berlin and Copenhagen could work. Most of the locals speak English, and there are so many foreigners that English is heard pretty regularly in bars and on the street. (Some of the foreigners are swaps between the two: lots of Danes in Berlin and Germans in Copenhagen.) In Copenhagen a number of the cultural events are also in English, e.g. http://www.scienceandcocktails.org/about.html http://www.scienceandcocktails.org/about.html and http://english.dadiu.dk/invitation-spilbar-14-0-surprise http://english.dadiu.dk/invitation-spilbar-14-0-surprise to pick two random science/tech ones.