On this trip we had only one instance when language was really a barrier for us. It was in Sofia, Bulgaria at the train station while trying to ask about getting from Bulgaria to Turkey. Because of construction and border issues the instructions for how to cross this border seems to change weekly, so it was legitimately a complicated task we were asking about. This complication, mixed with a language barrier between us and the train station employees made this portion of our trip a little bit of a headache and rather worrisome. We weren’t sure if we really understood their instructions, if we would know when to disembark the train, or whether we could even get into Turkey. Luckily, it all worked out in the end.
Beyond that one experience we had smooth sailing when it came to communicating.
Learning a few phrases also went a long way. We made such to look up the words for hello, goodbye, and thank you in each country. In many of the former Yugoslavian countries this was actually the same word.