Don't Sleep, There Are Snakes!

Don't Sleep, There Are Snakes: Life and Language in the Amazonian Jungle

This book recounts the author's 30 years of dedication to the Pirahã and their native tongue, "a mystifying system of sound and rules unrelated to any other language in the world. In this fascinating and candid account of life with the Pirahã, Everett describes how he learned to speak fluent Pirahã. He also explains his discoveries about the language—findings that have kicked off more than one academic brouhaha. Everett learned that Pirahã does not use what are supposed to be universal aspects of grammar." - "The language is claimed to have no relative clauses or grammatical recursion. Its seven and eight consonant phonemes (feminine and masculine, respectively) and three vowel phonemes are the fewest known of any language. There is a disputed theory that the language has no color terminology. There are no root words for color. The language does not have words for precise numbers."

Here is a wikipedia article about the the Pirahã:
Wikipedia article