In the play "Master Harold"... and the Boys, what roles do Harold's parents play in his life?

In the play, Hally's parents play a functional, yet distant role in his life.  Hally's father is continually sick (and he has a drinking problem), so Hally's mother finds herself in the position of having to care for the father's well-being.  Growing up, Hally was often taught things by Sam, and Sam did things with Hally that the father was unable to do.  For example, it was Sam who took Hally out to fly kites when his father was not able.  As a result, Hally does not look up to his father and is angry with his mother for always catering to his father's needs.