As an English language speaker, I knew there would be a language barrier from the moment I stepped onto European soil. First it was French where I was limited to knowing only a few phrases: "yes," "do you speak," "excuse me" and "thank you." As I was in Paris where English translations and bi-lingual citizens are common I didn't have trouble unless I was a train station (which I find funny as station workers interact with so many people, many of whom are probably foreign). When I bought my train tickets for my journey to Italy, the attendant didn't speak English well and even though it seemed like we communicated well enough, I ended up getting a ticket for the wrong date.
The morning I traveled to Tours, France I spent time at the station ticket windows trying to clarify or possibly change my overnight ticket to Italy. I went to 3 different windows, each subsequently sending me away to another window that were for English speakers and who could deal with the problem at the same time. Finally, when I arrived back in Paris, a Metro worker told me there was luggage storage at the Bercy station. There wasn't. I should have relied on the research I did at home. From then on I was going to do my best to not believe foreigners responses to my questions if I knew they didn't speak English well.
I had no problem with Italian in Rome, but the second I reached Siena I ran into many problems. Though Siena is a city, it is small compared to Rome therefore like many places, the farther you get from the metropolises the harder it is to find English. My attempts at communicating with the bus dude resulted in me believing that I could take any bus and it would take me to Piazza Gramsci. As I recounted here, it didn't.
The entire bus system is itself, a language barrier. Even when I was living in Tokyo, our orientation leaders advised us not to take the busses, or attempt to understand the bus system, unless we knew each bus' destination or could read and understand Japanese. Similarly, in Siena, the schedules were all in Italian, the driver only spoke in Italian, and even then he didn't announce the stops. Bus systems just don't cater to English speaking tourists. Therefore, in regards to Siena specifically, if you only speak English, I suggest bringing a map and walk despite the hills, or cough up the money and take a cab. My day certainly would have been less stressful.
Lucky for me, my language barrier problems ended in Siena and I had no problems throughout the rest of Italy and later in Germany and Austria. Though I knew less German than I did French and Italian, I learned from my earlier mistakes and changed my travel behaviors accordingly. It made for a less stressful vacation and if I ever go abroad again I will know how best to avoid all language barrier problems.