The characterization part refers to their qualities as a character. You may want to comment on their individual qualities and traits they possess as an individual as well as the traits they have as a couple. You may also want to include how other people outside of their relationship perceive them as a couple. Are they affectionate toward eachother, completely self-absorbed or do they isolate themselves from others? You may want to include how these traits that each character has may influence their behavior and choices they make all through the play. Does their culture play a part in how they act or how they are perceived? You may want to look at all these aspects to make your essay more rounded. To help you even further, before you even start, make a list of the characters and all their traits. Once you see all the qualities on paper that may help you draw ideas to write from.

how has this author established the characters and how do their relationships affect the way you see the play.

how do they relate to each other as individuals, in terms of when it was set, and does this give you any insight into how cultural encounters took place then and now?

compare and contrast these couples