"Muñi kepī issi."

Translation: They are mothers and fathers.

[zstelling]

Duolingo wants you to understand that that "kepī" specifically means "and [the] fathers," which is why the reverse order is deemed incorrect.

[Emarijacoway]

Once again, i put the subjects in a different order and the system told me i was wrong

[Lugui367]

why Muñi kepī issi ? If kepī is "the fathers" and kepi "fathers" ??

[Mariano.Yalour]

Lengthening the last vowel equals the meaning of the conjunction "and". I.e: They are mothers and fathers / They are the mothers and the fathers.
(There are no articles in HV)