To be rich, a nation must know the German language well do you agree Ukrainians no longer learn Russian the rich of Norway, Denmark, and Slovakia know the German language well
German, along with French and Italian is passé. It would be polite to learn German, but they speak excellent English regardless.
I think you're too hung up on pro-capita GDP. US beats all those countries. Ever been there? I'm here right now. And I'll tell you what...in terms of basic stuff like transportation and just general feel walking around the cities there are more poor people in the US.
It may be true for Slovakia. Norway and Denmark have close trade ties to Germany, but also to the U.K. (English). I think Norway and Denmark are more fluent in English than they are in German. The Baltic sea does allow for easy trade connections. I think also traditionally the Northern countries had much lower amounts of immigration, which kept poverty rates down and wages high, although that changed after the early 2000s.