This accomplished, Iago goes straightaway to Othello so that he can lead him to where Desdemona and Cassio are talking. As Iago and Othello view the scene, Iago plants seeds of doubt and jealousy in Othello's mind concerning Desdemona's fidelity. The scenario Iago suggests is that Cassio and Desdemona are having an affair. Later, fortune literally drops Desdemona's handkerchief into Iago's hand; he gets the handkerchief from Emilia, who discovered it, plants the handkerchief in Cassio's room, and then tells Othello that he saw Cassio with it. When Othello asks Desdemona about the handkerchief, she tells him that it was lost (which is the truth as she knows it). Cassio, meanwhile, has given the handkerchief to a courtesan with whom he is intimate. Iago manipulates a conversation with Cassio about his courtesan to make it appear to Othello—who is eavesdropping at the behest of Iago—that Cassio is talking about Desdemona.

His smoldering rage now beginning to bubble over, Othello tells Iago to kill Cassio and then angrily confronts Desdemona. In spite of Desdemona's protests of innocence (backed up by Iago's wife, Emilia), Othello is now convinced of her infidelity with Cassio. Iago, meanwhile, has Roderigo attempt to murder Cassio; when Roderigo fails to do more than wound the soldier, Iago slays him so that Roderigo can't implicate him in the affair. Othello strangles Desdemona in her bed. When Emilia discovers the crime, she decries the Moor as a villain and at first refuses to believe that Iago has so evilly manipulated Othello. However, Iago's appearance and subsequent answers lead Emilia to confront the fact that her husband is responsible for this tragedy. When Iago cannot keep Emilia from telling the truth about the handkerchief, he stabs her and attempts to escape; not only is he captured, but letters found on Roderigo's body thoroughly implicate Iago as the treacherous villain that he is. Faced with the shame of having murdered an innocent Desdemona, Othello stabs himself in front of Cassio and dies on Desdemona's bed, beside her.

[Quoted from Shakespeare Resource Center]

Study Questions for Shakespeare's Othello by JM Massi

Quoted from HeySmarty: Study Questions

1. How does the animal imagery used by Iago reveal his own attitudes toward blackness, women, and sex?
2. What clues can you find in Othello's words that he considers himself unworthy of Desdemona and that he thinks their marriage may be "unnatural?"
3. How does Othello's reverence, near adoration, of Desdemona contribute to his tragedy?
4. How does Desdemona's attitude toward her husband contribute to the tragedy?
5. Trace how the themes of white and black are paralleled by images of light and dark, day and night.
6. What rhetorical devices does Iago use to deceive Othello?