What is an example of a shift in the play Romeo and Juliet?

In Romeo and Juliet, the shift occurs when Romeo accidentally kills Tybalt in a duel. Up until this point, the violence in the play had been between rival gangs, mostly involving fighting in public spaces. However, Romeo's killing of Tybalt, a Capulet cousin, takes place within the Capulet household and directly involves the main characters. This event marks a turning point in the play, increasing the stakes and setting in motion a chain of tragic events that ultimately lead to the downfall of both Romeo and Juliet.