The sofa is new? should be allowed. It is a correct sentence in English, perhaps conveying a tone of surprise combined with the basic question.
I wrote "Is it the new sofa?" , but as expected , it has been ruled out. Expected answer was "The sofa is new?" But does not sound like a question, looks to be different than English.
Should it not be 'a sofá'? I thought sofá was feminine because it ends in 'a'.
sofá is a masculine word... some masculine words end in A in Portuguese.