From Wikipedia’s “PirahÃƒÂ£ language“:
The PirahÃƒÂ£ language is a language spoken by the PirahÃƒÂ£ – an indigenous people of Amazonas, Brazil, who live along the Maici river, a tributary of the Amazon.
PirahÃƒÂ£ is believed to be the only surviving member of the Mura language family, all other members having become extinct in the last few centuries. It is therefore a language isolate, without any known connection to other languages. Despite having only ~150 speakers as of 2004, in eight villages along the Maici, it is not itself in immediate danger of extinction, as language use is vigorous and the PirahÃƒÂ£ community is monolingual. …
Unusual features of PirahÃƒÂ£ include:
- One of the smallest phoneme inventories of any known language …, and a correspondingly high degree of allophonic variation, including two very rare sounds …
- The pronunciation of several phonemes depends on the speaker’s sex.
- An extremely limited clause structure.
- No grammatical numerals, not even “one” or “two”; the closest the language comes to numerals are general quantity words like [“a few”, “some”, and “many”].
- No abstract color words other than terms for light and dark.
- Few specific kin terms; one word covers both “father” and “mother” [and they appear not to keep track of relationships any more distant than biological siblings.]
- The entire set of personal pronouns appears to have been borrowed from Nheengatu, the Tupi-based lingua franca. Although there is no documentation of a prior stage of PirahÃƒÂ£, the close resemblance of the PirahÃƒÂ£ pronouns to those of Nheengatu makes any other hypothesis improbable.
- PirahÃƒÂ£ can be whistled, hummed, or encoded in music.
The occurrence of so many unusual linguistic features in a single language is remarkable.