A couple nights ago, I went over to the house of two friends about my age. They speak Spanish, English, and German. Their mom only speaks Spanish and German. There was a German boy who was living with them. He had showed up just the day before and didn't know any Spanish. He spoke German and English. I speak English and Spanish, but no German. Thus, whether Spanish, English, or German was spoken, there was one person who did not understand. Translating for them was trivial, with everybody at the table able to do so.