Further, do programming languages and math (each with their own definitions, notations, and axioms) count as language? I guess that would depend on how the brain processes these vs. spoken&#x2F;written language.<p>How about dialects and very closely related languages? Surely, say, Tamil (or Mandarin) and English are quite different or orthogonal even, while Tamil (or Mandarin) and Kannada (or Cantonese) have similarities having diverged more recently (~2000 years for Tamil and Kannada&#x2F;~1000 years for Chinese).