"I struggled only for you"
This short quote sums up what Heathcliff feels about the point of his existence. He has lived a struggle, and he pulls through it for Catherine. This ties in with the end of the novel, when Heathcliff no longer has any thing to live for other than to get revenge on Edgar.
"Devil daddy"
The religious comparisons between Heathcliff and the devil appear throughout the novel. It reenforces Heathcliff's negative persona
"I'm not your husband, you needn't be jealous of me"
Both Heathcliff and Catherine feel the same about each other at this point in the novel, however, both of them feel a resentment towards the other that means that they won't come together until the end.
"they were really in possession of a deep and growing happiness. It ended."
The use of the short sentence, "It ended", creates a sense of finality, that the return of Heathcliff utterly stamps out any idea of happiness.
"Settle my score with Hindly"
Heathcliff's need to settle his score with Hindly enforces his character, this idea that he lives only for Catherine and his need to become even with those that he feels have hurt him.
"love my murderer"
The admittence of Catherines love for Heathcliff is contrasted with this idea that he is her murderer, both hurting and praising Heathcliff.
"You and Edgar have broken my heart, Heathcliff!"
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"couldn't love as much in eighty years as I could in a day"
Heathcliff expresses his love for Catherine in comparison to Edgar, another example of the over dramatic way in which the emotions of the characters within the novel are conveyed.
"The single pleasure I can imagine is to die, or to see him dead!"
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"How would you like to live with your soul in the grave".
Heathcliff compares Catherine to his soul, this idea that without her he is soulless
