The biggest issue with Esperanto, is that it&#x27;s (from the wp page):&quot;The phonology, grammar, vocabulary, and semantics are based on the Indo-European languages spoken in Europe.&quot;<p>While that puts it in the same boat as English - it strikes me as slanted heavily towards the &quot;European dialects&quot;, rather than say, Farsi.<p>I actually think Japanese might make as good a &quot;universal&quot; language: it&#x27;s an old language - and has few sounds. I think (but am not certain), that one would be hard pressed to find anyone that wouldn&#x27;t be able to distinguish all the phonemes of Japanese (while many have issues distinguishing between &quot;tap&quot; and &quot;flap&quot; (&quot;r&quot; and &quot;l&quot; - right vs light)).<p>A big caveat is that I&#x27;m completely unfamiliar with African languages in general, as well as &quot;old&quot; American ones (both things like Navaho and Tupic or Macro Je). For use as a &quot;universal&quot; language, one would probably want to limit the vocabulary and reform the writing system in some way though. Perhaps choosing a subset of the existing Kanji and updating them to be more classic iconographic again.