"I protest, in the sincerity of love and honest kindness." III.iii.295. What I really don't like about Iago is how he switches from iambic pentameter to common speech depending on to whom he is speaking. With Othello and women, it is always iambic pentameter to show either how smart he is, or to show off his education and "superiority" respectively. But then when he is speaking to Cassio it's like he's talking to a five year old. He's not trying to use big words (as if that's possible in Shakespearean writing) and he speaks in common language. He's doing everything he can to make himself as similar to Cassio or Othello so that they think he's on their side. Not to mention, the insincere tone he has is really annoying. The reader knows that he's a jerk, but the characters don't. Yet.