Here are a few reasons why the narrator is not able to help Roderick Usher:
1. Limited Understanding: The narrator does not fully comprehend the extent of Usher's mental and physical illnesses. He is aware of Usher's sensitivity and anxiety but does not possess the knowledge or expertise to provide effective treatment or assistance.
2. External Forces: The narrator's ability to help Usher is also hindered by external forces beyond his control. These forces include the oppressive atmosphere and decaying condition of the House of Usher, as well as the supernatural elements that seem to be at play.
3. Incapacity to Intervene: The narrator is often paralyzed by his own emotions and fears, which prevent him from taking decisive action to help Usher. He becomes overwhelmed by the eerie atmosphere and the strange events that unfold in the house.
4. Limited Role: The narrator's primary role in the story is to serve as an observer and witness to Usher's decline. While he feels sympathetic and concerned for Usher, his role does not extend to actively intervening or altering the course of events.
5. Tragic Fate: The story portrays a sense of inevitable tragedy and decay associated with the House of Usher and its inhabitants. This suggests that Usher's downfall and the destruction of the house are predetermined, and the narrator's efforts to help would ultimately be futile.
Therefore, while the narrator provides moral and emotional support to Roderick Usher, he ultimately cannot prevent the tragic events that befall Usher and the House of Usher.