These are questions you would like the character to answer. Instead of Jocasta commiting suicide and Oedipus being exiled, the play ends with a trial. So, I need questions which the chacters on trial must answer. 1 example is -Jocasta why did you marry Oedipus, a man obviously so many years younger than you?
How about asking the shepherds why they didn't speak up sooner; one of them could have averted all of this grief and ugliness. What about the lone survivor of the incident with Lauis? Oedipus seemed to go through life with blinders on, and all he had to do was look around at things beyond himself. Why didn't he do that?
Perhaps you could ask Oedipus why he has been so proud and certain that he has nothing to fear. Why did he not abide by Teiresias' order to "never speak again to these men of me. Above all, why did Oedipus not ask his foster parents if they were his real parents after he learned of the prediction that he would slay his parents?
For Oedipus Rex, you might consider asking Jocasta why she remained silent even after she suspected that Oedipus was her son. It is possible that Thebes could have been spared some grief if she would have spoken. You might also consider asking Oedipus why he chose not to heed the warnings of Teiresias. These are questions about which we can draw conclusions; however, the play does not offer concrete answers for them. It might also be interesting to know why Jocasta chose not to heed her husband's orders and have Oedipus as a baby killed--she obviously had sympathy for the infant's life, but did she have any other motives?