Prashant Mishra
It was developed to communicate across the island's deep ravines and narrow valleys.
With virtually no outside contact, their language remains one of the most mysterious and least documented in the world.
Discovered only in 2008, Koro is a Sino-Tibetan language spoken by about 1,500 people in the Indian state of Arunachal Pradesh.
Suri (Ethiopia and South Sudan)
Known for their intricate lip plates and body painting, the Suri have a rich linguistic heritage that is still largely unexplored.
The Ainu language is spoken by the Ainu people of northern Japan. Once widespread, the language has fewer than 10 native speakers today.
It is known for its extensive use of click consonants, making it one of the most complex languages phonetically.
It is known for its complex grammar and unique cultural expressions, deeply tied to the land and traditions.