This is part of the difference between series.
The following is a reader submission:
Please detail the difference between “who” and “whom” in the following phrase:
. . . which helped to shape me into (who/whom) I am today.
Carmen
Thanks for writing, Carmen. This is a tricky one. The key to determining whether to use one or the other is determining what is the subject and object in the sentence.
You would use “who” because it is part of the clause “who I am”, in which it is the predicate pronoun to I. “Whom” is used if it is the object in a clause.
The trick is to substitute either “he” or “him” in the clause. If “he” sounds better, use “who”; if “him” sounds better, use “whom”. In this case, one would say “I am he”, not “I am him”.
An alternative would be to use “the person” in place of who/whom, as in: which helped shape me into the person I am today.
I hope that answers your question.
Let me know if you have any grammar questions, and I’ll be sure to post the question and answer here.