In the Middle Ages, English speakers actually pronounced the k and the gh in 'knight', a bit like German Knecht. The sounds changed; the spelling stayed. French tells the same story: the 'oi' in 'roi' (king) was once said 'oy', then 'rweh' at Louis XIV's court. Odd spellings are often snapshots of how people used to talk.
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.