Prince Nicholas of Greece and his siblings spoke English to their parents, and Greek to each other. while the King and Queen spoke German together and later Ellen of Russia spoke Russian with Queen Olga. From Nicholas' brother Christopher's memoirs, Christopher spoke six languages. i'm sure Nicholas spoke of course Greek, English, French, possibly German and some Danish, but i'm not sure about Russian, while Christoper can speak Greek, English, Danish, Russian, French, and Italian.