There’s an article in The Independent today about the Pirahã language. It is claimed the language has no words for numbers, colours, tense and other abstract concepts. Not only that, but the speakers of the language are said to be unable to learn it. If it’s all true, it would be truly sensational, but it’s hard to know what to believe when all I’ve read is an article written by a non-linguist interviewing a field-worker of unknown pedigree. I hope I’ll find something more reliable soon.
Update: There’s a good article about the language in Wikipedia. It confirms that most of the outlandish claims are due to Daniel Everett and have yet to be confirmed independently.