We say it almost everyday. When friends text to meet at 7. Ok. When your boss hands you an assignment. Ok. When you need to pay the bill. Ok. And so on.

Source: http://sploid.gizmodo.com/where-did-the-word-ok-come-from-and-what-does-it-actual-1716122767?utm_source=recirculation&utm_medium=recirculation&utm_campaign=tuesdayAM#_ga=1.96016476.1395629761.1436154276