Who is the narrator, can she or he read minds, and, more importantly, can we trust her or him?
First Person / Central Narrator
As a memoir, the narrative is of course written in the first-person. Thanks to this point of view, we're drawn in and get to see everything through McCourt's eyes (or rather the eyes of young Frankie). This is Frank's story as he remembers it. As a result, it's important to remember that Frank isn't aiming for veracity here. He's just trying to tell us what he remembers and as anyone who's retold a story knows, memories are tinged with emotions and those emotions change and affect the way we remember things. It doesn't mean it isn't true, it just means it's Frank's truth. (For more on this, see "Genre.")
Part of the genius of the memoir is that grown-up Frank who's writing the memoir manages to keep the perspective of the child experiencing the events he's writing about. Frankie sees and hears things he doesn't understand, and the grownup writer doesn't explain them; he just relates them as a child would experience them. As Frank gets older in the book, we get the perspective and understanding of an older and wiser child.