unfaithful using deception Iago's manipulations convince Othello He plants seeds of doubt in Othello's mind making him believe that Desdemona is unfaithful Look to your wife observe her well with Cassio Towards the end Othello kills Desdemona by the influence of Iago When everything becomes clear to him after killing Desdemona he commits suicide Cassio's Involvement Cassio's reputation as an honourable and trustworthy soldier is well-known to the audience Iago convinces Othello that Cassio is involved with Desdemona but the audience knows that Cassio is innocent There is no relationship between them However Iago becomes successful in this regard by manipulating Othello He uses the handkerchief as a tool of manipulation and Othello believes him blindly The Handkerchief The handkerchief that Othello gives to Desdemona holds great significance but Othello is unaware of its importance until it's too late He's unaware that its disappearance will be used against Desdemona later The handkerchief a significant symbol in the play is used by Iago to deceive Othello Othello believes that the handkerchief is proof of Desdemona's unfaithfulness as Iago has led him to believe He says That handkerchief which I so loved and gave thee Thou gavest to Cassio However the audience knows that the handkerchief was planted by Iago and its presence in Cassio's possession is innocent These instances of dramatic irony contribute to the complexity and suspense of Othello The audience is constantly aware of the characters' misunderstandings and misjudgments It leads to the tragic outcomes of the play