Rresearching the marvel of cognitive thought into human speech, no known cause exists for one of the most baffling questions in the study of human development.
There's a pub owner in Tavistock, England, who watches old B&W American gangster movies in hopes of learning to speak Brooklynese. Here's a primer he might love.
Non-human primates' capability for language is a result of their motivation, which lies in the importance of protection, social status, and for teaching skills.