Hi! 1. When and why did the Spanish substitute the personal pronouns nos and vos by nosotros and vosotros (in the nominative case)? My question is not about the existence or meaning of nosotros/vostros, they are understandable and corresponding forms do exist in other Romance languages as well. But why nos/vos do not exist any more in nominative plural, let's say "parallelly", as e.g. in French or Italian. An observation for curisosity: the personal pronouns generally tend to be relatively short, but nosotros and vosotros are from the "practical" point of view "inexpectedly" long ... 2. When and why did vos became os (in dative/accusative)? Thanks in advance.