you have to force them aswell to make barnbarnsbarn! However, your gammelgammelfarmor is probably gone already by that. https://dl.dropboxusercontent.com/u/2327889/Släktträd%20%282%29.pdf
I can help but LOL every time I found a word like barnbarn or mormor or event farbror in the course. It just make soo much sense that you can help but laugh. I wonder... why we do not see something like this in more languages?
JA!.. For many grandparents their grandchildren are walking "bonbons. So sweet full of surprises and wonderful things. By the way... What kind of "Bonbon" would you be for your grandparents? I think I would be a dark chocolate covered one with a sweet coconut paste and some brandy extract on it... Uff.. that is something just a grandparent will love ;-)
I never expected to find repetitive syllable in Germanic languages. They are very common in Bantu languages: "majimaji" means "watery", i.e. "A watery soup". "kichinichini" means "undercover" or "surreptitious". "motomoto" means the same as "moto" which is "hot", but when you say "motomoto" it is hyperbolic, exaggerated or insisted.
They're both the same: barnbarn.
However, you can often tell from other words whether we're talking about one child or more than one. In this case, since it says mitt, you know that it's a single grandchild, because mitt is a singular form. If it had been mina, you'd have know it was a plural.