So I was writing an first-person essay, and my Taiwanese English teacher told me that one of the sentence is missing the Subject "I", however my Canadian English teacher suggests that it is okay to ignore "I" if the narrator is yourself.
So here goes the sentence:
.... At first she disagreed, but after persuading her that scary movies are not real, she was convinced. ....
Okay, my Taiwanese teacher thinks that "persuading her" is missing the Subject, so we don't know who is doing that which is an obvious grammar error, while my Canadian teacher thinks it's okay to ignore the subject here, since the readers already know that this is a first-person essay, it should be the narrator "persuading".
Who is correct?