Jonas is a complex character. In literature, we describe characters are either round or flat, and static or dynamic. We also focus on character traits, or characterization, including of a character’s physical and personality traits. If you are writing an essay on Jonas, you don’t want to just list his traits. You want to analyze him. You can choose to write about a theme, or lesson, that Jonas learns, such as that difference should be celebrated and not feared.
If you decided to write your essay on Jonas’s transformation, you might discuss how he is a round character, meaning we know a lot about him, and a dynamic character, meaning he changes throughout the book. We know that Jonas is introspective or reflective, because from the very beginning of the book he is thinking and analyzing his feelings. He grows and matures through his relationship with The Giver, and he realizes that the way things have always been done is not good enough and the community needs change.