Board Thread:Warhammer 40k Novels/@comment-27376167-20151210113237/@comment-24091837-20160415010935

The Primarch may have simply used an forgotten/obscure language of Terra, or the language of whatever planet he was raised on to teach the Tau, or perhaps he had a gift for Telepathy, and perhaps thus he may have seen no need to teach them Gothic at all. Also he would have kept certain things secret from them until he felt they were ready to know them, or that knowing certain things may cause the forces of Chaos to take notice of them before they were possibly ready to deal with the danger that accompanies such attention.