N'kisi

http://www.skepdic.com/nkisi.html

https://en.wikipedia.org/wiki/N%27kisi

http://www.xf-world.com/moment-nkisi-met-jane-goodall/

N'kisi could speak 950 words in Jan 2004In 2003, he started learning English.

It was shocking he learned 317 words in just 1 year. And 26 words each month.