I was in Paris and I met someone in a store who did not speak English and I did not speak French. Turns out we both spoke Hebrew and had a nice conversation. (He was likely Sephardic as most jews in France are nowdays)
I was in Barcelona and someone came up to me and wanted information about the park. They did not speak English or Spanish and I could not help them. I then heard them speak Hebrew and I was able to answer all their questions and they had a real smile on their face and almost felt at home.