Relation between catherine and Heathcliff explain?

Catherine and Heathcliff's relationship is for the most part spiritual. As children their love for each other is innocent and only later after Catherine's accident becomes conditional. Whereas their initial love is based on tenderness and commitment, Heathcliff's determination to meet Catherine's conditions (which he does), only to return and find her married leaves them with a sense of unfulfilled passion..... the innocence is gone, jealousy and poor decisions prevail, and they punish others for the anger they feel for each other.