Proper nouns.
If proper nouns are allowed: Mississippi Missouri
In the question above, nouns and sentence are the only nouns. Neither of which are proper nouns.
The thing that distinguishes proper nouns from common nouns is that proper nouns are always capitalized. Common nouns are only capitalized as the first word in a sentence.
Proper nouns refer to specific names of people, places, or things and are always capitalized while common nouns are general names for people, places, or things and are not capitalized.
proper nouns = Helen, Romecommon nouns = table, computer
There are no proper nouns in the sentence.
Proper nouns are always capitalised, but adjectives are not.
The word December is a proper noun; the common noun is month.
Proper nouns are the unique names of people, places, or things. Common nouns are the words for general things. Pronouns always replace proper and common nouns.
Proper Nouns: Used to define the specific name of a noun. Common Nouns: The general form of nouns.
Two kinds of nouns are common or proper, singular or plural.