Part of US Astronaut training is to live with a Russian family (I don't think it is a Cosmonauts' family) and participate in immersive Russian language training

Part of US Astronaut training is to live with a Russian family (I don't think it is a Cosmonauts' family) and participate in immersive Russian language training. This is before they train on how to fly the Soyuz, and the Astronauts do serve as flight engineers on actual Soyuz missions to the ISS. There is a reason NASA does this.