Not so much the commas, as the lack of declensions. - You must kill me, Ioannes (vocative: John must kill you) - You must kill me, Ioannem (accusative: John m

Not so much the commas, as the lack of declensions. - You must kill me, Ioannes (vocative: John must kill you) - You must kill me, Ioannem (accusative: John must be killed)