Emily Bronte's Wuthering Heights, portrays the different human relationships that the characters have within the novel. The important theme in Wuthering Heights, how love can lead to both positive and negative outcomes, is based upon the characteristics of each individual and how their relationship is to each other. Bronte helped to develop this theme through the narrative structure of the novel.
This novel is written as a frame story - a story within a story. Nelly narrates most of the story to Lockwood and he translates it to the readers. This way, there isn't an omniscient narrator and we get to see the story through the perspective of actual characters within the novel. This gives more depth to the story and makes it a more realistic and believable feel to it, and because of this, the theme is emotionally felt and experienced more by the reader more. The narrative structure helps to develop this theme throughout the rest of the novel. .
Also, this novel is told as a look back into the past. The novel begins as Mr. Lockwood visits Heathcliff in Wuthering Heights. The strange behaviors of the people at Wuthering Heights make him curious about them. When he goes back to Thrushcross Grange, he asks Nelly to tell the story of Heathcliff's life. The flashback from the present to the past helped to develop the theme by leaving mystery and suspense to the reader. Showing Heathcliff's present state at the beginning of the novel as being one of desperation and isolation makes the reader wander what type of love can lead a man to become so miserable and lonely. This shows how love can have a negative effect on the characters. .
Next, the novel is told in two parts. When Nelly is telling the story to Lockwood, she first tells of the first generation and then there is a pause in her story. When she continues the narration, twelve years have passed and she tells the story of the second generation.