It is a play about the power of language. While, as Rebecca Warren says, "Elizabethan and Jacobean dramatists used language to establish and build dramatic atmosphere, to define time, place, and character", "language is not merely the medium by which the drama is conveyed: in this play language is action". What she means by this is that the tragedy depends upon language. Othello falls because he is manipulated to such an extent by Iago's language, the characters are illustrated through their use of it, and their power is exerted through its use, or deliberate lack of use. Therefore, the action and outcome of the play is largely determined by the characters ability to manipulate language. .
Iago is the most significant example of a character manipulating language in order to influence the events of the play. Although Shakespeare wrote in a mixture of blank verse (unrhymed iambic pentameters) and prose, he manipulates the style and form of the verse in order to achieve certain effects and creates specific idioms for each character. Of all the players, Iago is the most skilled and effective in the use of it; he slips effortlessly between prose and verse depending on his situation, and his intent. His idiom, his natural voice, is crude and makes frequent use of colloquialisms, obscenities and sexual innuendos and he uses this to impressive persuasive effect in his conversations with Roderigo. However, he also utilises another style; elegant and noble blank verse, a parody of Othello's idiom, and this can be seen, for example, in III.iii.465-72. Othello's idiom on the other hand, is dignified, measured blank verse befitting of his role as the noble and heroic Venetian general. G. Wilson-Knight described Othello's speech as "highly coloured stately rich in sound and phrase", and said that it shows a "uniquely soldierly precision" and "a peculiar chastity and serenity of thought". We see the power of his speech in the lines,.