Mallam is told to "shut up" whenever he tries to speak so that eventually the tea seller learned to swallow his words .why is mallam treated in the way what does this behavior towards mallam add to reader understanding of both his character and ghanaian society

Mallam was treated that way due to the fact he belongs to the low-class society. In Ghana, there are different social classes: The upper class where the rulers, nobles and similar people are part of it. The other is the middle class and the last one is the low and working class where Mallam is part. They have different rights, that's why Mallam does not have the right to speak before the higher class.