I was wondering whether someone would be able to explain the origin of the -s form as used to bind a predicate with a third person subject (he,she,it) to express a "simple " present sentence as in he has breakfast. Is there any etymologic hint to explain it.
If it results from a language evolution what is the need for adopting such a flexion as it doesn't seem to ring a meaningful bell in the mind of people (save for morphological habit) or does it mean it signals the binding of a predicate to a subject that is by definition absent and not in a position to assert the validity of the binding?