LitCharts assigns a color and icon to each theme in Harry Potter and the Cursed Child, which you can use to track the themes throughout the work.
Parenthood
Time, Mistakes, and the Past
Friendship, Family, Love, and Bravery
Reputation and Expectation
Death and Sacrifice
Summary
Analysis
Later, Albus arrives at Defense Against the Dark Arts class—only to find that Hermione is the professor. He is stunned that she’s teaching and that she’s not Minister of Magic, and she harshly tells him his stupidity has lost him 10 points from Gryffindor. Other students protest, saying that Albus is losing points on purpose because he hates Gryffindor. Hermione tells the students to be quiet and Albus to sit down, taking another ten points from them.
The play continues to explore the different problems and ripple effects that Albus and Scorpius have wrought on the present. Because Ron and Hermione never fell in love, Hermione lacked joy in her life and has become somewhat embittered, also leading her to be a teacher rather than the Minister of Magic. But it also shows that some things remain constant: even though Albus is not in Slytherin, he has not become popular, showing how expectations affected him regardless of the house he was placed in.
Active
Themes
Looking around, Albus asks where Rose is. Hermione asks who Rose is, and Albus says that Rose is her and Ron’s daughter. Albus quickly realizes, however, that because Ron and Hermione aren’t married, Rose doesn’t exist. Hermione grows furious, taking 50 points from Gryffindor as she starts to explain how to conjure a Patronus charm.
Here the play illustrates the dire consequences that fixating on the past and meddling with time can have. In trying to save Cedric, Scorpius and Albus have now made it so that Rose never existed, essentially killing Albus’s cousin.