Rule: The characters in fictional books exist only in the present, so you must always use the present tense to write about what they’re up to.
Note: If something happened to a character before the story you’re reading begins, you may use the past tense to refer to that event.
Examples:
Wrong: McMurphy was faking being crazy. (One Flew Over the Cuckoo's Nest)
Better: McMurphy fakes being crazy.
Wrong: Jane went from place to place making documentaries about meat. (My Year of Meats)
Better: Jane travels from place to place making documentaries about meat.
Wrong: Jay Gatsby discovered a beautiful dream. (The Great Gatsby)
Better: Jay Gatsby discovers a beautiful dream.
Practice:
Resources for further explanation of the fictional present:
Texas State's Verb Tense for Analysis of Literature
Collect Cengage's Present Tense