Don't have my books with me so I can't read up the fluff on them ... but I was suddenly wondering whether servitors can speak or not?
I'd say no since they are basically your morose lobotomized semi-machine servants. Yet I also read about a med-servitor, which seems to be a type that would need Intelligence-based Advance skill and at least the ability to ask its patients where it hurts ... though it would also be very 40K-like if such a servitor would forego such a question and just start operating