I'm reading a novel in which once in a while a character says something like "I are", "He do", and similar stuff. I understand the author is just reproducing the way people talk on the streets.
However I've found a piece of text of which I'm not sure if it's proper English. One of the characters, who almost always speaks proper English, is reproducing a conversation that happened many years ago using the present tense in the following manner:
I was with this guy and "Hi", says he, "how are you", says I...
and so on.
My question is if the "says I" is proper English (a special case in which "I" is treated as a third person because we are relating in present tense something that happened in the past) or it's just kind of slang.
I was also a bit surprised by how the usual order is switched ("says he" instead of "he says") but to me it's secondary to the "says I" issue.