why do the capulets and montagues hate each other

Shakespeare never explains why the Capulets and Montagues hate each other and are constantly fighting. P
A reader can make a few educated guesses though. PThe reader does know the feud has been going on for a very long time, and the reader knows that the feud is well known to the public. The reader also knows that both the Capulets and Montagues are wealthy and influential families in Verona.

PThose facts lead me to suspect that the feud originated over some kind of economic dealings that went badly. PIt makes sense that because both families are rich, they would each be upset over losing money or being out competed for more wealth.

PIt could be a political deal that went sour too. If both families are wealthy and influential, it makes sense that they are active in politics and city government as well. PPerhaps one family took advantage of a political ally in a way that hurt the other family. P Or maybe it was a forbidden love between two star crossed lovers of long ago.

P No one really knows. P It is an age-old feud that no one has bothered to explain to either Romeo or Juliet, but it just understood that every member of both families and even down to the servants of those families participate in on a daily basis. P Therefore, every time anyone from either household encounters a member from the opposing household in the streets, there is a quarrel of some kind.

P It is so bad that the Prince declares that the next person who causes disruption of the peace in his streets will be put to death. This is the reason Romeo has to run away after killing Tybalt for his revenge for Mercutio's murder.

P If Romeo stays in the city, he will most certainly be put to death for his disturbance of the peace and bloodshed. The feud has been in place so long, probably none of them could explain the true reason it began. sort of like the Hatfields and McCoys.