Final answer:
Iago manipulates Othello into believing Desdemona is unfaithful by insinuating infidelity and planting Desdemona's handkerchief with Cassio, exploiting Othello's trust and jealousy without making direct accusations.
Step-by-step explanation:
Iago begins to convince Othello that Desdemona is unfaithful by manipulating his emotions and planting seeds of doubt. He does this by using suggestive language and making veiled accusations against Desdemona's character. For example, he speaks of how women are capable of deception and infidelity, and hints that Desdemona may be acting suspiciously.
Iago begins to convince Othello that Desdemona is unfaithful by sowing seeds of doubt through insinuation and indirect suggestions. He does this by questioning Cassio's honesty and hinting at a secret intimacy between Cassio and Desdemona. Iago's manipulative tactics involve planting Desdemona's handkerchief, a token from Othello, in Cassio's possession to strengthen Othello's suspicions without direct accusations.
As the trusty ensign of Othello, Iago is careful never to present direct evidence, allowing Othello's jealousy and imagination to do the work for him.