Code-switching and code-mixing are the widely accepted phenomena in the everyday life of bilinguals. Pakistani English novels in which Pakistani speech communities and characters are depicted are the examples of these instances. The sociolinguistics types, reasons and context of the code- switching and code-mixing done by the characters are traced down in this work which proves that sociolinguistics theories are not only applicable to real life situations but also on the written representation of such situations by competent authors.