"Sylvie Dovaogēdy gerpī ipradas."

Translation: The wise Unsullied eats fruit.

[HaileyRoss14]

How can we tell when its unsullied singular and plural?

[Marcell663664]

Why is "The wise Unsullied eats a Fruit" wrong?

[Xenon-]

Because it is accusative plural:
Sing. Nom. gerpa |
Sing. Acc. gerpe |
Pl.Nom. gerpi |
Pl. Acc. gerpī