"I work in Germany, although I live in Poland."

Translation: Pracuję w Niemczech, choć mieszkam w Polsce.

[marcogom]

chociaż works as well :)

[lunatix17]

A very common thing among Polish people living near the border ; just compare the average salary of the 2 countries...

[TheMarrta]

pomimo = mimo

[Jellei]

Added "mimo, że".

[StartPlayer]

To help learn declension I looked up Niemczech and Polsce on wiktionary. Apparently Germany is 'plural' and Poland in 'singular'. Is there a reason for this? I expect this will be the same for other countries. Is there a rule or just one those things you have to learn?

[Jellei]

I don't think there's any rule (apart from the logical assumption that island countries called "XYZ Islands" have plural names, same for "Stany Zjednoczone" = "United States"). Some countries have a plural name and you just need to remember them. They include such countries as Niemcy/Włochy/Węgry/Indie/Chiny (Germany/Italy/Hungary/India/China).