C. Letterforms in context

Although we generally say that Nastaliq letters have four forms (two if they’re nonconnectors), in fact there are often subtle differences depending on which particular letters are surrounding them. For instance, the tooth of a medial be-series letter is smoothed out before a re-series letter, and initial chhoṭī he loses its divot when it is followed by alif or lām. The chart below, inspired by a similar one in C.M. Naim’s Introductory Urdu, shows how various letters change in different environments: