why isn't 'the spanish woman cannot read' a possible answer?
“The Spanish woman cannot read” would be “Femina hispanica legere non potest.” Different ending on hispanic_.
What is the part of speech for "hispanice"? And what is it's declension and case?
I believe it's in the ablative case/declension. The usage here I guess is an "ablative of manner"-- referring to the manner in which she reads ("Spanishly" or something like that, if we want to go super literal).
The 'in' should not be required.