If “her” is objective and “she” is subjective, why do we say:
‘Who is she?’
‘Who is her?’
apart from the latter sounding a bit strange?
‘That car belongs to her.‘
‘She has a nice car.’
Is the second sentence, ‘Who is her?’, actually grammatical and is there a situation where it is appropriate? (Or am I just plain wrong in thinking that “who” is the subject in both questions?)
It is incorrect that “who” is the subject, “she” is still the subject. If it wasn’t a question it would be “She is who”. Because it’s a question it is inverted.