Originally posted by BowmannIt should be 'I'm I.'
Correct would be "I'm me."
The verb to be is intransative and, as such, does not take the objective noun form
but the subjective as a predicate. This is why it is grammatically correct to say 'this is he'
rather than 'this is him.' It sounds funny because everyone says it wrong, but grammatically,
it is a perfectly fine sentence.
And, yes, 'I' is not a proper noun.
Nemesio