I am being stupid as well, so sorry! But isn't that kind of normal for a gifted kid? My oldest is verbally at 99.7th, and my third child is two nearly three and not tested but I assumed gifted as well as she's reading a bit etc. Poeple think she's going to school next year although she's not going for three years. She says things like "Mum, (person) says you have to write her a letter so I can have cows' milk at creche." But she can't say "k" or "g" sounds or "th" and sometimes we have to ask her to repeat herself or translate for other people or use a word in another sentence. Yes she sometimes finds this frustrating as do we. But I would not have pegged it as abnormal.
Apologies if I have missed the point.