Shouldn't the English "translation" of federal be simply "federal"? The other adjective for being federated is "federate."
Sorry, I'm not an English teacher but I play one online. :-)
Hmm... I don't have either a good grammar or spelling, as you can see, mostly because my English is not that good, because I was born on Colombia (lol, if you asked why did I did the article here it is in a nutshell) but I think you can say "federative". And I know it's a Republic, I don't know why did I include "federative". Fedelede 14:14, July 2, 2010 (UTC)
I might be of help. My stepmother is Colombian, my father works for the US government there (full position is classified) and I have dual citizenship in the US and Costa Rica, and I have been a fluent Spanish speaker for most of my life. La Republica de Colombia is the official name, but since the US has a reputation of naming its puppet states "federal" republics, (Federal Germany) then I guess it would be La Republica Federal de Colombia. Arstarpool 15:04, July 2, 2010 (UTC)