"Slavic Translator" in WWII

[yakimicki1]

My grandfathers parents were from Galicia/Austria (Modern Poland near Ukrainian border, Lubaczow area),,, ethnically Ruthenian/Ukrainian.
They spoke 'Ukrainian', 'Polish', and even reported speaking 'slavic'.
When my grandfather was in WWII (USA), he was considered a 'slavic' translator. At the end of the war he helped get people from the concentration camps back to thier villages.
This idea of speaking 'slavic' leaves me a bit curious. My grandmother says that he could talk to people from many different countries.
Do you think he spoke more than ukrainian and polish? Are those two languages close enough to other languages in eastern
europe that one could communicate easily?

[Volodya987]

Not easily, but essentially YES