In Whom^x, Before and After^x

September She was still left with a feeling of sadness, although it had been almost two weeks since the event. She still didn’t know what to believe... yet the proof was there, in her very sadness among other things... Her grandmother had passed away and she had no such feeling, on the contrary,...

The positions before and after a form of to be are both nominative case positions. (who, she, he, etc.). The correct forms therefore never include whom in these structures. Who is it? Who is the president? Who can that be? Who might that be? Who will be there? Who might be in the...