when the person picking up the phone is just the one wanted on the phone, he /she may say:"this is he/she". But the sentence seems a bit strange at sencond glance. Why not "this is him/her"? Thank you for any help.
***** NOT A TEACHER *****
(1) As the distinguished teachers have already told you, there is a lot
of controversy regarding this matter.
(2)
NEVERTHELESS, there are a few people who are interested in
upholding the highest standards of English grammar.
(3) Since you teach English, you know, of course, that traditionally,
one uses the nominative case after a linking verb. So in choice
English, one says "This is she/he."
(4) It is true, of course, that nowadays most people say "This is her/him."
(5) You will have to make a decision -- insist on choice English
or go along with what is now popular.
P.S. In some cases, it's a matter of social survival. If a big, tough
American football player said "This is he," probably some people would
accuse him of being a "sissy" or even a person who prefers romantic
attachments with his own gender. In other words, for some people it
takes moral courage to speak "correct" English!!!
(6) As a teacher, you -- of course -- wish to give your students the
best education possible. I sincerely feel that when your students
write English in international correspondence, they will receive more
respect if they use choice -- rather than popular -- English.