I want to write a story that is told ONLy through one person's mind; what this one person is thinking and saying, with no other characters speaking. How would you go about formatting it?

All would be told in direct action as seen through the narrator's eyes (known as first-person limited point of view) and with no dialogue.

http://en.wikipedia.org/wiki/Point_of_view_(literature)

When writing a story that is told exclusively through one person's mind, there are various ways to format it. Here is a suggested approach:

1. Use first-person point of view: Since you want the entire story to be portrayed through one person's mind, using the first-person perspective (I, me, my) is a suitable choice. This will immerse the reader in the character's thoughts and experiences.

2. Establish a clear narrative voice: Create a distinct voice for your main character that reflects their personality, thoughts, and emotions. This will help the reader connect with the protagonist and understand their perspective more deeply.

3. Structure the story with inner monologues: Instead of conventional dialogue with other characters, focus on the protagonist's inner monologues. You can intersperse these thoughts with the character's actions and descriptions of their surroundings.

4. Utilize italics or quotation marks: To differentiate the character's inner thoughts from external narration, you can use italics or quotation marks. This will help the reader distinguish between what the character is thinking versus what they are verbalizing or experiencing.

5. Enhance readability: To make the narrative flow smoothly, consider incorporating elements such as paragraph breaks, dialogue tags, and transitions between thoughts and actions. This will improve the readability and comprehension for your readers.

Remember, with this story format, you have the freedom to delve deep into the character's mind and explore their thoughts, emotions, and introspections. Be creative in bringing their inner world to life, and ensure the story engages the reader by presenting a compelling plot and character development.