Proper nouns are names of specific people, places, or things. They are always capitalized in English.
Here's a breakdown of why letters aren't used:
* Capitalization: Capitalization is the standard way to distinguish proper nouns from common nouns.
* Clarity: Using letters would be confusing and ambiguous, especially if there were multiple proper nouns in a sentence.
* Consistency: The convention of capitalization ensures consistency in writing and helps readers easily identify proper nouns.
Example:
Instead of using letters like "A" or "B" to indicate proper nouns, we would write:
* Incorrect: "The A went to the B."
* Correct: "The John went to the Park."
Therefore, letters are not a standard or effective method to indicate proper nouns. Capitalization remains the established and universally recognized practice.