As an editor, I was trained not to edit dialogues to retain the realism of whatever language the character speaks, only recasting for clarity if necessary and changing obvious typographical errors. However, I make exceptions when the whole manuscript is problematic, meaning even the narrative paragraphs are written poorly. For example, my style is to avoid “kinda” in narrative paragraphs, allow them in dialogues, and consider retaining when the narrative is told in the first-person point of view.
I am considering this style in writing Filipino novels—that is, strictly using mayroon, kailan, baywang, tainga in narrative paragraphs and allowing their pronunciation spellings meron, kelan, bewang, tenga, respectively, in dialogues. Some Filipino novels, however, use the correct spelling consistently, even in dialogues. There are times that they feel unnatural to me, especially when the characters have quirky personalities. If the novel is set in the fifties or sixties, then terms may be spelled formally as they are.
What do you think?