Here's why:
* Proper Adjectives: These are adjectives that come from proper nouns (names of specific people, places, or things). They are always capitalized. For example:
* American (from America)
* Shakespearean (from Shakespeare)
* Victorian (from Victoria)
* Sunday School: This phrase is a compound noun, referring to a specific type of school. While it has a specific meaning, it doesn't derive from a proper noun and doesn't need to be capitalized.
Example:
* Incorrect: I went to Sunday School on Sunday.
* Correct: I went to Sunday school on Sunday.