Here's why:
* Proper nouns are specific names for people, places, or things. They are capitalized.
* Common nouns are general names for people, places, or things. They are not capitalized.
"Spoon" is a common noun because it refers to a general type of utensil.
Examples of proper nouns include:
* People: John, Mary, Queen Elizabeth II
* Places: Paris, Mount Everest, California
* Things: The Mona Lisa, The Great Wall of China
Let me know if you have other questions!