The Piraha people of the Amazon river basin live an existence unthinkable to most of us, one that consists of hunting, gathering, fishing in the Amazon and occasionally bartering with passing riverboats.

Despite sporadic contact with westerners for over two centuries, Piraha culture has remained largely intact.

Nowhere is this more obvious than with language although long exposed to Portuguese, the Piraha speak their own language and show no interest in learning anyone else's.

Dan Everett is a linguist who decided to do what no outsider had ever done before learn to speak Paraha as well as a native. This would not be easy, as Piraha has the reputation of being the most difficult language in the world.

It contains a very small number of vowel and consonant sounds, with the result that words tend to be long and intricate in order to provide the necessary variety of vocabulary. Moreover, being a tonal language like Chinese, the pitch of one's voice (high, low, ascending, descending) changes the meaning of the word.

There is no written alphabet, so Everett had to rely on native speakers, who spoke no English, to teach the language to him, who spoke no Piraha.

This was a tall order by anyone's standards, and it got even taller as Everett discovered numerous fascinating, unexpected surprises. Piraha lacks number words for anything other than one (more than one is simply
referred to as 'more than one'), and altogether lacks colour words.

There is no past tense, no creation mythology, no history — because the cardinal cultural value for the Piraha is immediacy of experience. Anything that is not experienced directly by the speaker, or at least reported by a speaker who learned of it from someone with direct experience, is of no interest to a Piraha listener.

Everett, whose ulterior motive for studying the Piraha was to translate the Bible and convert the population to Christianity, found this an insurmountable obstacle to his task.

Whenever he tried to preach about Jesus, his Piraha listeners would interrupt him to say, 'Have you met him? When did you talk to him?' Upon learning that Jesus was in fact long dead, and Everett had never met him in person, the Piraha immediately lost interest in everything about him.

But even this was, linguistically, speaking, not the most unusual thing about the Piraha. Everett talks at length about the idea of 'recursion', a linguistic term which means, essentially, that some sentences contain other sentences within them (in the form of relative clauses, for example).

So the sentence, 'The dog that was barking ran toward the car' could be said to contain two sentences 'The dog was barking' and 'The dog ran toward the car'. Every language in the world contains some form of recursion — except one. Guess which one.

For linguists, this is hugely important. Various linguistic theorists, Noam Chomsky among them, work with the idea of a 'universal grammar', the notion that all languages share certain key grammatical elements. Some theories even posit that language is itself a biological function — that grammar is not something we learn, but is wired into our brains.

Grammar is thus literally what makes homo sapiens different from other species of animals. The key to this theory is that all languages contain certain concepts, such as recursion.

After all, if all human brains share biological sources for language concepts, then all human languages should have these concepts. Everett's claim that Piraha does not is, therefore, significant. If he is correct, the whole theory of 'universal grammar' comes tumbling down.

Of course, because only Everett can speak Piraha, only he is in a position to decide whether or not his claim is true.
After 30 years of intermittent work in the Amazon, Everett found himself confronted with the startling realisation that his inability to convert the Piraha to Christianity had left negative consequences on his own faith. He gave up trying to translate the Bible and became an atheist, alienating his wife and children in the process.

It was an unexpected conclusion to a long, taxing but ultimately fruitful relationship between an isolated culture and an individual who did not belong to it. Everett's book, which serves as both a chronicle of his experience with the Piraha and a contemplation of their singular language, is a fascinating look at both the society and the man who studied it.

Don't Sleep, There Are Snakes Life and language in the Amazonian jungle
By Dan Everett
Pantheon, New York
ISBN 0375425020
283pp. $26.95