Surrounded by Indo-European languages such as French and Spanish, Basque belongs to no proven language family: it's an 'isolate'. It survived the spread of Indo-European languages across Western Europe several thousand years ago. Linguists know of dozens of other isolates around the world, such as Ainu in Japan and Burushaski in Pakistan.
In Kuşköy, a mountain village in northern Turkey, people talk across valleys by whistling Turkish. A 2015 study showed that whistled Turkish draws on both hemispheres fairly evenly, whereas spoken Turkish relies mostly on the left. The physical form of the signal, it turns out, matters to the brain.
Speech has no gaps between words. In 1996, researchers played 8-month-old babies a continuous stream of made-up syllables for just two minutes. The infants picked out the 'words' by tracking which syllables tend to follow one another. That's probability calculation, done without a calculator or any visible effort.