Dr. BPK,
I am chugging through your LKG material, in unit 3.2 now. I'm really enjoying it :) One of the biggest difficulties has been pronouncing υ and οι. I'm working at it and I'm getting better, but something that would really help me stay strong is understanding why υ and οι are pronounced as [y] in your system. How do you know that this is correct or the best guess/approximation?