How we cite our quotes:
"Are you possessed with a devil," he pursued, savagely, "to talk in that manner to me when you are dying? Do you reflect that all those words will be branded in my memory, and eating deeper eternally after you have left me? You know you lie to say I have killed you: and, Catherine, you know that I could as soon forget you as my existence!" (15.25)
Catherine torments Heathcliff until he day she dies – and beyond. Importantly, this moment is the only time that Heathcliff confronts Catherine on her behavior.
"Loving!" cried I, as scornfully as I could utter the word. "Loving!" Did anybody ever hear the like! I might just as well talk of loving the miller who comes once a year to buy our corn. Pretty loving, indeed! and both times together you have seen Linton hardly four hours in your life! Now here is the babyish trash. I'm going with it to the library; and we'll see what your father says to such loving." (21.140)
Nelly Dean tries to knock some sense into Cathy regarding her affair with Linton Heathcliff. It's interesting to note how gutsy Nelly is in the way she talks to Cathy. After all, Nelly is a housekeeper and Cathy is the master's daughter.
The intimacy thus commenced grew rapidly; though it encountered temporary interruptions. Earnshaw was not to be civilized with a wish; and my young lady was no philosopher, and no paragon of patience; but both their minds tending to the same point – one loving and desiring to esteem, and the other loving and desiring to be esteemed – they contrived in the end to reach it. (31.110)
With all the reasons in the world to dislike each other, Cathy and Hareton still fall in love. Their mutual sympathy changes the tone of the novel and allows for something of a happy ending.