Spanish, 80s


a group children hang out in the neighborhood and play together. Just for fun, they invent their own language (maybe gibberish), and swear to speak only that, including at home, which causes some friction. Meanwhile, several of their families decide to go to the beach together, and the children go play together on a cave by the shore. Then there is some kind of danger, and they have to speak. The police arrive, and when they persist to speak in that way, the parents swear they don't understand them.