Julius Caeser: Brutus' role as the tragic hero?

I have to write an open response answer on a test in a few days about Brutus' role as a tragic hero in the play Julius Caeser by Shakespeare. I understand the qualities of a tragic hero (i.e., haramatia, fatal flaw, etc.) but am unsure of how this progresses for Brutus. I would really appreciate an easy to understand answer, as my teacher has confused me so much with this entire play. Thanks for any help! :)