166. What was the answer?

On another occasion on the same island, Inspector Craig met another native and asked him: "If someone were to ask you whether it is true that two plus two is four, and you decided to answer in your native language, would you answer 'bal'?"

And this time, too, Inspector Craig did not record what the native answered ("bal", "yes", "no", or "da"). In his notebook, it is only noted that from the received answer, Inspector Craig was able to conclude who he was talking to: a zombie, a half-zombie, or an ordinary person.

What did the native answer to Inspector Craig's question?
166. And in this task, just like in the previous one, the native must be a half-zombie, and the only answer by which Craig could determine who his interlocutor is must be "yes" (in the native dialect). If the native had answered in English, Craig would not have been able to determine who he was talking to, since both a human and a zombie would have answered "yes" to his question if "bal" means "yes," and "no" if "bal" means "no." The native, answering "bal," could have been either a human, a zombie, or a half-zombie.