In the Spanish of the ballads the article is regularly used with a noun in the vocative.
The abandonment of the vocative for a new subject is artless.
The interjection of the vocative is with some hiua, and with others me.
The Irish form of the first is tuathtach: of the second thuathchin (vocative).
But "Your Royal Highness" is not a vocative: it can be used only in the third person.
It ought to be in the vocative, and you have put it in the dative.
Ahaygar; a pet term; my friend, my love: vocative of Irish tagur, love, a dear person.
The vocative alone often takes a final a as in the interrogative form.
"No, sire:" Scudamore scarcely knew what to call him, but adopted this vocative for want of any better.
Of the seven Slavic cases, only the nominative and vocative remain to it; all the rest being supplied by means of prepositions.
mid-15c., "showing the person or thing spoken to," from Middle French vocatif (fem. vocative), from Latin vocativus (casus) "(case of) calling," from vocatus, past participle of vocare "to call" (see voice (n.)). The Latin is a translation of Greek kletike ptosis, from kletikos "related to calling," from kletos "called."