Most common language used in BO?

It's in the German-speaking region. Aside from German, I think English will be more useful there than Italian.

Excellent- Thank you for your answer! :)

Here's a good visual of the different language areas in Switzerland.....

https://en.wikipedia.org/wiki/Languages_of_Switzerland#/media/File:Map_Languages_CH.png

The German spoken in Switzerland is slightly different than that spoken in Germany.

Swiss Germn is the first language in the Berner Oberland. Although the Swiss speak dialect among themselves, I have found that most will switch to Hochdeutsch when speaking to foreigners like us. Or they will use English.

If you want to learn a few words in German, include the Swiss greeting Grüezi ( or if to more than one person, Grüezi mitenand which means greetings among us). "Danke" ( thank you) and "bitte" (please) are universal.

Although Switzerland has four official languages, each is confined to a specific region, as shown on Ken's map. My personal experience has been that people tend to speak the language of their own region and not cross over ( unless they are celebrities like Roger Federer, who is fluent in many languages). The second language is more likely to be English than one of the other Swiss languages. Thus I encountered people from Suisse Romande ( the French-speaking area) in a mountain hut in the Berner Oberland, who knew no German at all, nor English. They saw food (Rösti mit Ei odor mit Wurst) going by but had no idea what it was or how to ask for it. I speak some German and enough French to get the main idea across, so I explained to them in French. None of the German-speakers around seemed willing to help with this.

The exception would be in the areas where Romansch is still spoken, where you will see this language on signs and maybe hear it spoken, but everyone needs to know a more widely-known language like German as well.

My experience is the same as Lola's, with one exception:

"I have found that most will switch to Hochdeutsch when speaking to foreigners like us. Or they will use English. "

That's what I had read too, but that's not what I found. When I was in Luzern and tried to use my "German" (which is rudimentary), people did not switch to either High German or English, but responded in Swiss German. So, I quickly learned that for anything important, I started in English; they then responded in English. (Even my German teacher - a native speaker, from near Cologne, says that when two Swiss Germans are speaking to each other, she has great difficulty understanding them! Interestingly, she can understand Yiddish with no problem).

So, for your situation, have the allergy cards in German and English for the Berner Oberland. French won't help there; of course, if you are also going to French-speaking Switzerland, have cards in French and English. I agree with Lola that French is not regularly used in German speaking areas and vice-versa, and when it is, it is very much a third language after English.

Alas, Italian will only help you in Italian Switzerland. The languages of Switzerland are German, French, Italian, and Romansch, and they are VERY MUCH in that order of importance and prevalence nationally (regionally, as we're all saying, is a different story).

"Alas, Italian will only help you in Italian Switzerland."

In my experience, that's not entirely true. On a visit to Chur a few years ago I went to a restaurant close to the hotel for dinner. The servers appeared to only speak German and NO English, so I was in somewhat of a quandary about how I was going to order dinner. At about that time an Italian speaking group arrived and the staff dealt with them in Italian. I can manage to some extent in Italian, so that solved the problem!

OTOH, in Locarno I often find more German being spoken than Italian. In Appenzell, Romansh seemed to be common with a few people.

I've found that many Europeans can speak multiple languages, so it's just a question of finding a common language. English is not always one of them, depending on the area. On a trip a few years ago, I shared a train compartment with a Swiss businessman who could speak seven languages! I knew he was telling the truth as during the trip, he chatted with me in English, and did business on his phone in several other languages. Amazing!

I find the languages in Europe one of the most interesting aspects of travelling there.

Hello! Sorry for being so terrible at replying quickly- as a teacher, I've been swamped with end of the year performances, etc. and I usually end up reading replies late at night when I'm half asleep and then end up re-reading and responding over the weekends. Anyway, I'll definitely get the card in German for my allergies- I have to say this was actually a really interesting read from all of you! I loved what everyone had to say and the extra info like the map actually led me to reading up more about it- it really is kind of fascinating! :) (one of the great things about traveling I guess, right?). Anyway thanks so much- as of tomorrow, we're 20 days and counting! :)

I find the languages in Europe to be one of the most fascinating aspects of travelling there. In addition to the basic languages in each country, there are also dialects and other differences. For example, in Spain you'll find Spanish, Catalan and Basque (among others). In Italy there are numerous variations from standard Italian as each region has their own version. The language spoken in Liguria or Florence will be somewhat different from that in Naples or Calabria. In the Dolomites (Italy), you'll more likely hear German being spoken. In Switzerland, I've been told that the German spoken in Lauterbrunnen is very slightly different to that spoken in Stechelberg which is just up the road a few km.

For me, the Central / Eastern European languages are the most difficult to grasp - languages such as Polish, Hungarian, Czech, Croatian, Bosnian, etc.

Perhaps it's said but true, the international language of tourism is English. You can always find someone in a tourist location who will speak English.

At least for the next few years, until Chinese takes over.