Final answer:
In Chapter 29 of Wuthering Heights, Heathcliff says that Catherine has disturbed him for 18 years.
Step-by-step explanation:
In Chapter 29 of Emily Brontë's novel Wuthering Heights, Heathcliff reveals that Catherine's influence has disturbed him for 18 years. This marks the duration of their intense and tumultuous relationship, which began when they were children. Catherine's presence in Heathcliff's life is a central theme in the novel, representing their deep connection and the destructive effects of their love.