In English, the words to describe the total absence of anything or anybody (and other similar meanings) are nothing and nobody, whose etymologies are quite direct: "no thing" or "not any thing" and the some for "no body" or "not one body".
In Spanish we have nada and nadie. According to RAE's dictionary:
- Nada comes from Latin [res] nata: "born [thing]".
- Nadie comes from nadi which comes from Latin nati: "the born ones".
So what I would like to know is: how did words that meant the existence of someone ("the born ones", "born things") come to mean the total absence of anything or anybody?