Here's why:
* First Person: The narrator is a character in the story and uses "I" and "me" (e.g., "I went to the store").
* Second Person: The narrator directly addresses the reader, using "you" (e.g., "You walk into the room and see a cat").
* Third Person: The narrator is an observer outside the story, using "he," "she," "it," and "they" (e.g., "She went to the store").
There's no established grammatical structure for a fourth person perspective, which would be a point of view outside of the traditional three.
However, there are ways to *mimic* a fourth person narrative in speech:
* Using a collective pronoun: You might hear someone say, "One would think that..." or "People say..." These are not direct addresses, but rather a way to speak from a generalized perspective.
* Using a detached voice: Someone could speak in a detached and objective way, as if observing a situation from a distance. This might be done by using impersonal language and avoiding personal pronouns.
It's important to remember that these are just ways to create the *effect* of a fourth person narrative. There is no official grammatical definition or usage for this concept.