One example of dramatic irony in speech is when a character says something that is true, but that they do not realize is true. For example, in the play "Romeo and Juliet," Romeo says, "I am fortune's fool." He does not realize that he is actually speaking the truth, as he is about to be killed by fate.
Another example of dramatic irony in speech is when a character says something that is false, but that the audience knows is true. For example, in the play "Hamlet," Hamlet says, "I am not mad." However, the audience knows that Hamlet is actually quite mad.
Dramatic irony can be a powerful tool in storytelling, as it can create a sense of suspense, humor, or tragedy. It can also be used to explore themes such as fate, free will, and the nature of truth.