Not quite the same thing but my son has delayed speech and has a vocabulary around 12 months behind his peers. He struggles so much with it that sometimes I forget that he is more advanced than he sounds. The net effect is that he will sometimes surprise you by saying something that needed a lot of insight and awareness in his reduced vocabulary, you forget that he has more going on upstairs than his speech would signify. I was taking him and his sister somewhere a few weeks back. To himself he said "This is not the fucking playground" which to me was both hilarious and encouraging as he never knowingly swears in front of us. So not only was he expressing his displeasure he using his own internal language to do it which includes words that Mum and Dad don't want to hear. Encouraging I think.
My aunt maintains that I walked through her door at 18 months old and said "that goddamn volkswagen broke down again." Brain development is crazy to watch. We did sign language with the kid before she got particularly verbal - she still uses some of them.