The noun 'meatballs' is a common noun, a general word for a form of meat dish.
A proper noun is the name of a specific person, place, or thing; for example Mama Lucia Italian-Style Meatballs or the 1979 Bill Murray movie "Meatballs".
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.
It is a proper noun, because it is the name of a specific thing.
proper
Proper noun
Pencil proper or common noun
it's a common noun. a proper noun would be Spider-Man.
Proper noun or common noun
The word meatballs is a plural concrete common noun with a regular plural (because the plural ends with -s.)
The noun cassette is a common noun.
a common noun?
Camel is a common noun.
The answer is proper noun. Examples of common noun and proper noun are: Proper noun: Mary Collins Common noun: monkey