How men first learnt to invent words is unknown; in other ...- ý nghĩa của sanitizer trong punjab ,How men first learnt to invent words is unknown; in other words, the origin of language is a mystery. All we really know is that men, unlike animals, somehow invented certain sounds to express thought and feelings, actions and things, so that they could communicate with each other; and that later they agreed upon certain signs, called letters, which could be combined to present those sounds ...