"The ham is stuffed with cheese."
Translation:Perna farta caseo est.
It seems like the Latin and English don't line up in this sentence. If farta is simply an adjective in the Latin, then it seems like "There is stuffed ham with cheese." would be the more accurate translation (with cheese being an ablative of accompaniment). "stuffed ham" would be how you use stuffed as an adjective in English. "Is stuffed" is certainly a passive verb form in English, but then in the Latin "fartus est" would be a past tense.
Perhaps the better English phrase is "the ham was stuffed with cheese". This would be consistent with how the course required us to translate "natus est". Those two should be translated consistently. If we can't say "is born" for those exercises, then we shouldn't be taught to think "is stuffed" in this exercise.
You noticed a difference but reached wrong conclusion that both phrases should be translated consistently. Latin has quirks that formal teaching and grammar books lay out and Latin-Speaking kids would have grown up with and with Duolingo we are supposed to accept. The verb to be born / nascor, nasci, natus sum is one of them.
farcio, farcire, farsi, fartus sum is a regular verb and that last and fourth verb form is used for past passive constructions with forms of sum. I am stuffing the ham with cheese. Active voice. Pernam caseo farcio
The ham is stuffed with cheese. Passive voice Perna farta caseo est (some hand waving making farta more of an adjective than a participle as Duolingo doesn't cover passive constructions). The verb to be born / nascor, nasci, natus sum is in a group of verbs called Deponent Verbs which are constructed as passive forms (which Duolingo doesn't cover) but have active meanings. So the last (yet third form) is used for past active constructions. For bonus confusion, in English the meaning for this specific verb is passive, tho the Latin is active .
He is being born (passive in English) Nascitur Active meaning in Latin
He was being born Nascebatur
He was born Natus est