Why is "sylvie" the correct translation? There isn't an accusative, is it?
"Sylvie" is an adjective that refers to the subject, which is in the nominative, so no, there is no accusative. However, there are a couple of adjectives that end in -ie for the solar/lunar nouns in the nominative. "Dovaogēdy" is a lunar noun.
Pretty sure any object, that normally would be accusative, changes to nominative case with the verb "to be". As in "Vala syyz issa" or "Vala kepa issa"
A language needs a fix: https://forum.duolingo.com/comment/29385663