Plot hole: Early in the movie, the principal from Precious' school buzzes Mary's apartment intercom to talk to Precious about alternative education. In order to hear what the teacher is saying Precious has to press the 'Listen' button, but occasionally the teacher can be heard speaking through the intercom even when Precious isn't holding the listen button.
Clareece 'Precious' Jones: Some folks got a light around them that shine for other peoples. I think that maybe some of them was in tunnels, and in that tunnel, maybe the only light they had was inside of them. And then, even long after they escaped that tunnel... They still be shining for everybody else.