I've tried to search for an existing thread on this topic, but I couldn't find one....(Sorry if one does exist and this has to be merged with it .)
In Spanish, a 'redundant' pronoun is often used, such as le in this (rather odd ) sentence I took from an online dictionary:
"Acostumbro a hablarle a mi perro"
Where does this "redundant" pronoun originate? Is it a relic from an earlier stage of the language where it was necessary?