The children are used to having people around that don't speak their language. The tribes are joining together with the French and Spanish around and it's the kids of all the tribes that pick up the language first and translate for the adults. But Jack's is so different.
Once the stranger starts speaking instead of just listening and watching them they all perk up and close around him in an even tighter circle. Their just as interested in being understood as Jack is. The stranger is the only adult really giving them any heed and not bossing them around. The girl just looks lost. She's wondering if it's his chest he's trying to bring attention to. The boy is the one to first speak up. He's been quiet so far and has taken it upon himself to guard the girls in case this man is dangerous. "Ack?"
Another one tries. "Jack!" The J sound isn't used very often but this child has heard it from another tribe. He grins at the others, being the first to get it.