Storybook reading is a powerful (and enjoyable!) language development activity. Watch this clip of a teacher reading in a preschool classroom.
How do the children demonstrate their interest? What new skills are they learning?
When reading storybooks with an adult, children typically like to comment on favorite characters and events, ask and answer questions, and talk about how the story relates to their own life experiences. Over time, as they become more familiar with the story, they like to retell the story and put the story in their own words.
And you know you have a good book when they are sometimes quiet (listening to the story) and sometimes active (talking about the book)!