It simply depends on what the proper nouns in question are. For example, if it's a joined last name, like Rodriguez-Jones, then of course it's hyphenated. It has nothing to do with whether or not it's a proper noun.
Examples of traditionally hyphenated compound nouns are:blue-greenfive-year-oldjack-in-the-boxjack-in-the-pulpitmother-in-law, father-in-law, sister-in-law, brother-in-lawsix-packT-shirt (or tee-shirt)x-ray
Plural nouns are not capitalized, unless they are proper nouns.
The common noun is person; the proper nouns are Spaniard and Spain.
Only if "the" is the first word in a title.
The nouns Texas and Austin are proper nouns, the names of specific places.A proper noun is the name or title of a specific person, place, or thing.
no never
A compound noun is a word made up of two or more words to form a word with its own meaning. There are three types of compound nouns, closed (bathtub), hyphenated (fifty-five), and open (bus stop).A proper noun is the name of a person, place, or thing; a proper noun is always capitalized. Examples of compound proper nouns:Queen Elizabeth IIYellowstone (National Park)Coca-Cola
Examples of traditionally hyphenated compound nouns are:blue-greenfive-year-oldjack-in-the-boxjack-in-the-pulpitmother-in-law, father-in-law, sister-in-law, brother-in-lawsix-packT-shirt (or tee-shirt)x-ray
In the question above, nouns and sentence are the only nouns. Neither of which are proper nouns.
Plural nouns are not capitalized, unless they are proper nouns.
proper nouns = Helen, Romecommon nouns = table, computer
There are no proper nouns in the sentence.
The common noun is person; the proper nouns are Spaniard and Spain.
The common nouns are: capital and state.The proper nouns are: Texas and Austin.
Only if "the" is the first word in a title.
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.
None of them are proper nouns. They are all common nouns that refer to colors.