Shakespeare is prone to the use of rhyme to illustrate the intellectual capabilities of a character, ergo his class, as a character that is able to speak with such fluency is obviously of a high intellect. He is respected even by those above him in the political hierarchy, evident in the words of the Duke as he makes contact with him referring to him as “Valiant Othello, we must straight employ you”. The sanity of Othello is maintained at this point, as he has the apparent ability to keep his personal life from interfering with his occupation, he himself stating “My speculative and officed instruments/ that my disports corrupt and taint my business.”
The setting in Cypress is contrasting to that of Venice, and it is important to understand this in order to draw parallels between the violent and turbulent nature of Cypress to that in the deterioration of Othello’s character. As Iago is able to plant the seed of doubt concerning the fidelity of Desdemona in Othello’s heart, we as an audience are able to see a change in the mannerisms and personality of Othello, and as Iago’s “poison” works itself into this insecurity of Othello’s (the tragic flaw of the character), the manipulation of himself begins to degenerate the character 'Work my medicine, work, work.”. Othello becomes manic, blinded by love and a lack of self-worth, and this is evident in the pace, tone and structure of his speech.
The other reason for repetition is the blatant emotional change in Othello, as he lets go of all that he has achieved, his status, his valour, and his sanity. The final line bringing an end to the noble Othello known to Venice as he farewells his occupation, contradicting his earlier statements in regard of his personal life affecting his public life. This change is flush with the bestial imagery created by Iago to describe Othello earlier in the play, using “'black ram', and 'Barbary horse' as indications of what he truly believes Othello is.
Othello’s newly acquired bestial nature eventually makes itself apparent upon his public assault on Desdemona, and is also the first point in which other characters from the world of the play are able to see the deterioration of Othello as his problems with his private life are seen in public with this abominable act. This leads to Roderigo to comment 'My Lord this would not be believ'd in Venice'. By bringing up Venice at this point is create a stark contrast, as the audience is able to visualise the honourable respected Venetian Othello in direct comparison to the savage like acts of Othello emphasized by the anarchy of Cypress. The astonishment in Roderigo’s comment also shows the obvious change in Othello.
In Conclusion, Othello's descent into lunacy is seen through his inability to separate private feelings and public duties, and through setting, Shakespeare signals the changes which occur in Othello's character and make it consistent with his surrounding transformations. The characterisation of Cypress and Venice is significant, depicting the transformation of Othello's character, and overall emphasising the tragedy of the play.