the statement that King Paul spoke NO greek is ludicrous. He use to Broadcast to the Greek People during WWII when he was with the Greek Gvt in exile from Cairo and London.
i will have to go back through my book but i have read that they spoke German after they married b/c The Queen Didn't know greek yet. I can't find the Source Right now but I emailed the webmaster at the Greek ROyal Website so maybe I will get an answer. just fyi .. King George I spoke Greek, Danish, English, German and French and would often in mid conversation switch from 1 to the other depending on who was present. on 3/18/1913 "he told his sons in English (which none of the Greek officers present understood that in october he would celebrate his Golden Jubilee and that he would take advantage of that and abdicate". ("Kings of Hellenes by John Van Der Kiste , page 74). Also, Queen Frederica ,In her book, she says she spoke German and English to Pavlos, German in person and English over the phone and in letters. She also states that they spoke Greek to the children, However, Sofia's German is flawless and her English has a German accent, so I think that's the language she heard from her mother as a little girl.
also, just FYI, there are tons of Youtube Videos of HM King Constantine II, HM Queen Sophia, and HRH PRincess Irine speaking Fluent Greek on Youtube so just throwing that out there.