Commissioned by the Kangxi Emperor and completed in 1716, this dictionary lists 47,035 characters. Nobody knows them all: many are variants or archaic forms. Reading a newspaper takes far fewer. According to an official list drawn up in China in 1988, about 3,500 common characters cover more than 99% of modern texts. By the end of primary school, Chinese pupils are expected to recognise around 3,000.
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.