What is one way to distinguish proper nouns from common nouns?

One way to distinguish proper nouns from common nouns is to look for capitalization.

* Proper nouns are capitalized because they refer to specific people, places, or things. For example:

* John (person)

* New York City (place)

* Mount Everest (place)

* Facebook (thing)

* Common nouns are not capitalized because they refer to general categories of people, places, or things. For example:

* boy (person)

* city (place)

* mountain (place)

* social media platform (thing)

Note: There are exceptions to this rule, such as titles that are always capitalized, like "President" or "Queen."