During these chapters we learned about the different pronouns. You did a recap already on the demonstrative pronouns.
Now, you are going to learn about two new types of pronouns.
Have a look at these two videos, where you'll hear the different types of explanation.
Object Pronouns https://www.youtube.com/watch?v=aqJMbCvduhY
Interrogative Pronouns https://www.youtube.com/watch?v=qRr3zqo9Kmo