Quoting Muke Tever <muke@...>:
> > As far as I can work it out, grammatical change follows phonological
> > change,
> > because the phonemes tend to collide, eg:
> >
> > Latin ending -us loses -s, -um loses -m, degrades to -o
>
> Didn't the -s actually remain for quite awhile? I know it's still remnant
> in Old French.
It seems not to be gone at all in Spanish - names like "Marcos" is supposed to
be reflexes of nominatives used as vocatives in late Latin. That Spanish
masculines typically nonetheless end in simply -o is supposed to be due to
accusatives simply replacing nominatives for no phonological reason.
Andreas