A new study of an Amazonian language describes a unique intersection between speech, gestures and the human concept of time. People who use Nheengatú, a language spoken by Amazonian people living where the borders of Brazil, Ecuador and Venezuela meet, point to where the sun would have been in the sky rather than speak a word to signify time of day.
For instance, if someone speaking Nheengatú wanted to explain that they saw a fish at noon, they might simply speak the words "I saw a fish" while pointing a hand straight up to the sun's noontime position, regardless of what time it is when the conversation is taking place.
Although Nheengatú has no numerical or written system for telling time, the language does use both spoken (auditory) and gestural (physical/visual) components to convey the concept, finds research from Netherlands' Max Planck Institute for Psycholinguistics published in the journal Language. While most human languages include grammatical constructs like nouns, verbs and adverbs, Nheengatú also includes gestures as part of its formal grammar system.
So languages don't only incorporate signing to replace a spoken word or to emphasize something; rather gestures can have their own meanings. And when you include gestures in languages like this "celestial pointing," it suggests there may be deeper ways of understanding existing and extinct languages, as linguists studying historical languages often refer primarily on written records.
Nheengatú is based on the language of the indigenous Tupi people of the Rio Negro area. It was formalized in the 17th century by European Jesuit missionaries with the hope that a lingua franca, or universally understood language, would simplify communication between disparate groups of people. Though it was the Amazon's most widespread language for several centuries, only about 19,000 people speak Nheengatú today, with more than half living in Brazil.