proprio is singular masculine. propria is singular feminine propri is plural masculine proprie is plural feminine
propio and propia are wrong
I tried the same with a question about beans once - Duolingo also translated "fagiolo" as "second-year university student". Put it in just for kicks, it threw a fit, presumably over context. I feel it's a little unfair though. Surely if they give us multiple translations for a word, they should let us use any of them?
In the preceding exercise they translated costume as "outfit." I used it for this one and got it wrong! I answered, "she has her own outfit." I also didn't realize until reading this discussion that there is a list a acceptable translations to vocabulary, but I'm sure they have given"outfit" as a translation for "costume."
I don’t have an issue with the word ‘costume’. My query was why the correct answer was shown to be ‘He has her own costume ‘. I thought it should be He has “his” own costume. Just a small point but frustrating. Anyway - maybe these answers get tweaked over time. It’s all good learning! Ciao!