so the software is probably written in embedded bytecode... :-) but the user interface of the clock is available in about 15-20 languages, including German;

GPS records the geolocation if GPS signal is received, no matter where in the world; the conversion into a track is then done after uploading to the Garmin server. In Italy, I used the "Map" feature to see on the watch while I was running which route I was taking (only a line, without waypoints or background map; but you can see exactly a circular route and how long you still have to the starting point). What also works: Create a course in Garmin Connect, load it on the watch and then it navigates for you with left/right instructions.... no matter where you are.