Why isn't this genative ie. your eyebrows? sprancene tale (I am not sure if eyebrows is feminine)
In Romanian, we don't usually use the genitive (sprâncenele tale) for body parts in phrases like this one, where the owner was already identified (ai = you have).
"Sprânceană" is feminine, but "eyebrow" is not -- in English, nouns lost genders a long time ago.