The Chaná language (Chaná: Lanték 'speak' or 'language'; from lan, "tongue" and tek a communicative suffix) is a Charruan language, spoken by the Chaná people, in what is now Argentina and Uruguay along the Uruguay and Paraná Rivers on the margins of the Río de la Plata. It was spoken by the Chaná from pre-Columbian times in the vast region that today is between Entre Ríos Province, Argentina and Uruguay, and the Uruguay and Paraná Guazú Rivers. According to recent oral memory narratives, in ancient times, they inhabited territories around the current Brazilian margin of the Uruguay River. They later migrated from this location along the Uruguay and Paraná Rivers from the outfall of the Iguazú River and from the Paraguay River to the current location of Asunción. Today, there is only one person who can speak Chaná, Blas Wilfredo Omar Jaime, and prior to his discovery of the fact that he was the last speaker, he had not used Chaná for many decades, eroding his memory of the language. UNESCO recognizes it as a living language but also as "extremely endangered" because it has only one native speaker. The Chamber of Deputies of the Entre Ríos Province recently recognized the necessity for the government to recognize and protect the language.

The following are the phonemes of the Chaná language:

Lanték has been recognized as a part of the "Cultural Heritage of the Entre Ríos Province." The first dictionary of the language was published by the Provincial Publishing House of Entre Ríos. The publication contained a dictionary compiled via Don Blas Wilfredo Omar Jaime and an encyclopedic study of Chaná culture. There were also several chapters on the linguistics of Chaná by Viegas Barros.

The Chaná cultural study encompassed the fourth and last section of the book. A great deal of Chaná ethnoliterature was obtained during elicitation sessions with Viegas Barros during the seven years prior to the publication of the volume. It also has an audio CD which includes recordings of Don Blas speaking his Lanték.