What are the key moments in a classical Greek tragedy?

In a Greek tragedy, we expect to see the fall of a tragic hero. This is done by the hero having a tragic flaw (called hamartia in Greek terms). In many cases, the tragic hero falls as a resulf of 'hubris' (this word means excessive pride). After being set up for the fall, we expect a moment of 'anagnorisis' in which the hero makes an important discovery, often realising the error of their ways. As a result, the audience is expected to feel a sense of 'catharsis' (a sense of their own emotions being purged by watching the trials and tribulations of the hero), allowing the audience to leave the theatre feeling refreshed.