Here are some examples:
* People: John, Mary, Queen Elizabeth II
* Places: London, Mount Everest, the Sahara Desert
* Things: The Eiffel Tower, the Mona Lisa, the Bible
Key Features of Proper Nouns:
* They are always capitalized.
* They refer to specific, unique entities.
* They are not preceded by articles (a, an, the) unless they are part of a title or name.
Let me know if you'd like more examples or want to explore specific types of proper nouns!