Boy, interesting. There's no indication of the sex of "you" in this sentence, but "Non sei l'unica" was ruled "incorrect." I reported it, but am I missing something? Is there a reason "l'unico" would be the only right answer?
Just a few questions ago, both "Sei l'unico" and "Sei l'unica" were given as correct translations in the answer box for the English sentence "You are the only one". I don't see why they wouldn't both work here as well. I got the version of this question in which we have to choose either " l'unico" or " l'unica" to fill in the blank: Non sei ___. They both seem right to me. How do you choose only one?
you're mistaken. 'l'unico' is masculine and 'l'unica' is feminine not 'la unica'. here is a website that may help. http://www.uvm.edu/~cmazzoni/3grammatica/grammatica/articles.html