"I live in Warsaw, in Poland."
Translation:Mieszkam w Warszawie, w Polsce.
I commented on this already here: https://www.duolingo.com/comment/12704087 but I guess it will be more handy for many people if I also copy-paste it here (links do not work on mobile):
It's like "a" and "an" in English. If it gets too hard to pronounce a wild 'e' appears.
The rules are not so easy as in English though. Basically if the noun begins with "w" or "f" followed by yet another consonant, there will be 'we' before. So for example:
we wtorek (on Tuesday)
we Francji (in France)
we Wrocławiu (in Wrocław)
w wojsku (in army)
w Finlandii (in Finland)
It also works with the word 'mnie' (me):
- We mnie (in me)
In other cases, when the word begins with at least two consonants both options are allowed:
We śnie* / w śnie (in a dream)
We mgle* / w mgle (in a fog)
We Środę / w Środę* (on Wednesday)
We Czwartek / w Czwartek* (on Thursday)
I marked the one that seems more natural to me with *, but as I said both are OK.