Answer:
The two families have been taught to hate each other, and this hatred impacts on the family members and the citizens of Verona.
Step-by-step explanation:
In the prologue it says that the hatred between the two families is ancient. The Montague's and Capulet's hated each other, because their families have been at an ancient feud and they are just maintaining what their ancestors did. Shakespeare does not give a out front reason for why the families hate each other. Quote: 'Here's much to do with love but more with hate' and 'my only love sprung from my only hate'.