"Hello, my name is Marcus."
Translation:Salve, mihi nomen est Marcus.
I know latin through French so the grammatical terminology might no be the same in English. A latin noun is composed of two parts the theme which holds the meaning of the word and does not change, and an ending which holds the grammatical function. The first never (or rarely) changes, the 2nd has a declension. Marcus is a noun of the 2nd declension. -us is nominative (subject...) and -e is vocative (apostrophe). So if you want to say : how is Marcus doing ? You'll say "Quid agit MarcUS ?", but if you're talking to Marcus and want to say "hey Marcus, how are you doing ?" you'll say "salve MarcE, quid agis ?"
You need the right declension. Marcus is the nominative form, Marce is the vocative form.
I understand that they want the very specific, "mihi nomen est" yet I can't help but to feel a lil cheated when this isn't clearly stated at the beginning of the exercise (or at the part the exact question pops up), since I was taught in school to use "nomen meum est" and duolingo won't accept this as an answer
Marce vs Marcus is vocative vs nominative. Direct address vs the subject of the sentence.
Here is a plain-English overview of what the cases are and how they work:
Latin cases, in English
Adjectives must agree in gender, number, and case with the nouns they modify, but they have their own declensions. Sometimes you get lucky and the adjective just happens to follow the same declension as the noun, but that is not a guarantee.
You mean the genitive "meus", right? Verbs of state do not take direct objects, they take subject complements.
Both ways are valid: "Nomen meus est Marcus" and "Nomen mihi est Marcus".
"My name is Marcus" and "The name to me is Marcus".
That's just how things are said in Latin. Irish does something very similar. Irish does not have a verb that means "to have", so instead of saying "I have an apple", they say "An apple is at me".