I see. We would call those kratek and poln chlen, but I'm not sure if we have those. So you are saying that the a at the end of um-a is because of this?
That's funny but when I say: "Jaz sem shla s Uma", the a at the end would be there because of the padezh (3.sklon). I don't even think about the a at the end of your translation, because I'm naturaly inclined to read everything in padezh
Interesting.
EDIT: I just thought of some more words in srednji spol (middle gender), and they don't just end in -o...there are also others ending with -e (like okolje-environment, dekle- girl, zhrebe- little horse)