They spoke German because they were "Germans" living in Russia. My parents and grandparents spoke German but I never heard them speak Russian. They came to the US in 1908 from Russia but were of German descent. They settled in the Dakotas. Are you or your family from that area? We are probably related somehow. You can find my family tree on "Ochsner-Fauth" family tree on ancestry.com. Maybe you will find a Fauth relative in common with me by looking at it.