An internal monologue is the thoughts that a person expresses silently to themself. In literature, an internal monlogue of one or more of the characters is termed an interior monologe, and is a tool that authors use to make their characters come more alive by silently expressing their thoughts and feeling. All stories are built around conflict, and this can be internal conflict as well as external conflict. The only way to express internal conflict is by reporting the character's internal monologue. It can also be used ro deepen the character by, for example, high-lighting their fears, their secret passions, or thier ability for self-analysis, and is a way to establish their voice. It can be used to show their past through their memories.