For seven nights in a row the narrator would sneak into the old man's room. On the eight he killed the old man. This is again and again because the narrator did it for seven nights in a row so we wonder what he is going to do next and he keeps doing it.
The Narrator always talks about how he loves the man but he hates his eye. This is again and again because he said it more then once.
The narrator killed the old man. This is character contradiction because he said he loved the old man.