What are possible essay questions that can be asked about Monopolies (apart from the good and bad of a monopoly)?
If you do not want to discuss the pros and cons of monopolies, you are pretty much left with talking about why monopolies come about.
The best essay question I can think of then would be "What factors, both "natural" and "unnatural" cause monopolies to form in an economy?"
By asking (and answering) a question like this, you would come to understand why monopolies form. You would understand that some monopolies make sense (are good) while other monopolies are not. You would also get to understand the conditions that have to exist in order for monopolies to come into being.