Act 1,scene 3

Isabel differs from both Mr. M and Thami in one very significant way: she is white. She also attends Camdeboo High School, which is not just an all-girl school, but also an all-white school. Isabel holds a high place in the dominant white culture yet has no problems mixing with blacks in the educational setting.

Mr Know Thami And Expect Thami to listen to him as An Elder and Thami as Child/young Learner, but he doesn't know Isabel as He Knows Thami. That's why he cannot predict isabel's response