One way an individual learns through sensation is when they watch someone else do something. The best way to learn is to see it being done. For example, when someone sees a broken-down car, he or she does not know how to fix it. The best way for them to learn is to see it being fixed, and then they can learn from that experience. This same thing goes for a child. Their vocabulary is not pre-existing. Rather it is learned, or sensed from the world around them. They listen to their parents and other people around them and pick up words here and there, until their vocabulary has become big enough to speak.