Long stretch but what if biblo doesn’t speak common language.

Whatever the inverse language name is called. He doesn’t speak Japanese/english etc.

When chopper heard him earlier he told Saul he just taught biblo was the quiet type and when biblo began talking or hooting chopper seem shocked.

What if biblo doesn’t speak the language and chopper is surprised as he never met an animal he couldn’t understand it just sort of clicks automatically.

Biblo begins speaking and chopper can’t make sense of it and tells them he’s speaking gibberish and repeats some phrases he says to which Robin looks around surprised and tells chopper she understood what he said. The language he’s speaking is of the ancient language.

So to understand what biblo says chopper begins translating him trying to repeat what he says while Robin listens to chopper and begins translating the words into their own language until she can make sense to what he’s saying.

This is also to ensure that biblo doesn’t spill to much info on the void century or whatever so not to spoil us on what information will be on laugh tale.