POTO AND CABENGO

Poto and Cabengo are identical twins (real names Grace and Virginia Kennedy, respectively), who used a language unknown to other people until the age of about eight. Poto and Cabengo is also the name of a documentary film about the girls made by Jean-Pierre Gorin and released in 1979.

They were apparently of normal intelligence. They developed their own communication because they had little exposure to spoken language in their early years. Poto and Cabengo were the names they called each other.

Apparently a lot of the words and phrases the girls used were focused around potato salad.

"Pinit, putahtraletungay." (Finish, potato salad hungry)

"Nis, Poto?" (This, Poto?)

"Liba Cabingoat, it." (Dear Cabengo, eat)

"La moa, Poto?" (Here more, Poto?)

"Ya." (Yeah)

Wikipedia