"Hello, Marcus and Livia."
Translation:Salvete, Marce et Livia.
Marcus is second declension (-us) and Livia is first declension and here they are in the vocative singular form. Second declension (-us) nouns take -e ending for the vocative case, while first declension uses the -a which matches the nominative case. If I remember correctly, only the second declension (-us) nouns take a vocative form that is different than the nominative.
Because Marcus ends in -us in the nominative, and in -i in the genitive, and Livia ends in -a in the nominative, and in -æ in the genitive.
Thanks. But quite hard to get one's head around, particularly as the course hasn't covered this stuff. There's a lot here for a newbie; not least, peoples' names and declensions. Is this suitable so early?
When directly addressing someone or something we make use of the vocative case. This is done here since we are saying 'hello' directly to Marcus and Livia. The reason Marcus changes to Marce is because it is second declension and the nominative singular ends in -us. With these types of nouns the vocative singular ending is -e.