Before their Soviet masters were kicked out, I was meeting with an official of the Polish Central Bank in Warsaw once. We had never met, and it was my first visit to Poland, so I asked him what language he wanted to converse in, and offered him a choice of English, German, Russian and French, figuring he was most likely to know one of them. He chose Russian, I said fine, and off we went. About 45 minutes later, an assistant dropped to ask something, and the boss introduced us. The assistant, whose English was fine, immediately started in speaking English to me when he heard I was from the United States. The boss joined our conversation--in perfect English--adding a few comments.
I asked him, hey if your English is that good, why did you want to speak Russian all morning? He said, "oh I just wanted to hear of you could do it."