Let me say something else as well
In the first eight Conversation units, we have covered practically all the grammatical forms of Panjabi words used by educated speakers of the central variety of the language. But it is equally important to learn how these different forms of words (especially of verbs) are combined to express different varieties of meaning. We have already come across some combinations of the forms of main verbs and helping verbs. In Panjabi and other North Indian languages (including the languages spoken in Pakistan, Bangladesh and Nepal), different forms of main verbs and auxiliary verbs can be combined in hundreds of different ways, each combination expressing a different shade of meaning. It is obviously impossible to deal with all such combinations in this basic-level course. If you decide to learn Panjabi (or any other North Indian language) at an intermediate or advanced level, you will have to learn to use all these combinations. They look and sound complicated at first. But if you know the meanings of the individual members of a combination, the meaning of the whole starts making sense. After all, a Panjabi-speaking child masters all such combinations by the age of nine or ten!