Dramatic Irony: Talthybios' comments on Polyxena
When Hecuba asks after her daughter Polyxena, the herald Talthybios replies, "She has been assigned to serve at Achilles' tomb" (48); "she has found her lot in life. She is free of trouble" (49). The audience already knows that Polyxena has been killed because it was mentioned in the prologue as well as being commonly known. Therefore, there is dramatic irony in his words because we, the audience, know something the character does not. This contributes to our pity for Hecuba.
Verbal Irony: Kassandra's "marriage"
Kassandra, a pledged virgin priestess, is to be given to Agamemnon as a concubine. When she enters the scene, she conducts a flurried mock marriage ceremony for herself, but she tinges it with irony. She proclaims she is "...offering the torch to you, Hekate, / to illuminate the marriage bed" (51); Hekate is the goddess of witchcraft, the night, and dark magic. Kassandra thus clearly indicates her antipathy to her "marriage" and her attempt to thwart it as best she can.
Situational Irony: Noble Birth
Andromache mourns the imminent loss of her son, telling Astyanax, "The noble birth of your father has been the cause of your undoing" (72). Normally, one's noble birth would be a trump card, a form of protection against woe. At the very least, it would seem to suggest security, comfort, luxury, and care. Here, though, noble birth means death; it means eradication. Andromache may or may not be tinging her words with verbal irony, but there is certainly situational irony here in that our understanding of the privileges of nobility has been upended.
Verbal Irony: Andromache
Andromache knows she is plunder and belongs to Neoptolemos now, but for a few moments, she retains some hope that her son Astyanax will grow up and perhaps restore Troy to its former glory. She is rapidly disabused of this hope, however, and says grimly, "I am headed for a splendid wedding celebration, / now that I have lost my child" (72). Her verbal irony makes the audience even more aware of her tremendous loss, bleak future, and the trauma of war that is visited upon women and children.