"The vegetarian eats a potato."
Translation:Ο χορτοφάγος τρώει μία πατάτα.
I didn't think of it ... before I checked the ... because I needed help to spell the word. Under it it says m/f nom. m/f that is, it can be both male and female.
So I tried "Η χορτοφάγος τρώει μία πατατα" but that did not make Duo happy :(