No. The compound noun "Sunday school" refers to certain religious education, not merely school held on Sunday. In any event, the proper noun Sunday would be considered a noun adjunct, or attributive noun. In many cases, Sunday would be called an adjectival noun, because it is a form of the prepositional phrase "on Sunday" as in "We will go to church Sunday."
It is neither: it is a proper noun for a holiday.(In 'Easter Sunday' it is a noun adjunct with the proper noun Sunday.)
The possessive form Sunday's is an adjective. The word Sunday in "Sunday paper" is not an adjective but a noun adjunct, because Sunday is not a characteristic of paper.
Because Sunday is a noun, and, by definition, an adjective is used to modify a noun, all that needs to be done to use an adjective in a sentence with the word Sunday is to choose a desired adjective and use it to modify the noun "Sunday". For instance, one could say "A gloomy Sunday." Or, "A busy Sunday."
The proper adjective for George is Georgian.
The proper adjective for Siam is Siamese.
It is neither: it is a proper noun for a holiday.(In 'Easter Sunday' it is a noun adjunct with the proper noun Sunday.)
The possessive form Sunday's is an adjective. The word Sunday in "Sunday paper" is not an adjective but a noun adjunct, because Sunday is not a characteristic of paper.
Because Sunday is a noun, and, by definition, an adjective is used to modify a noun, all that needs to be done to use an adjective in a sentence with the word Sunday is to choose a desired adjective and use it to modify the noun "Sunday". For instance, one could say "A gloomy Sunday." Or, "A busy Sunday."
The proper adjective for southwest is "southwestern."
The proper adjective is Haitian.
The proper adjective for Portuguese is "Portuguese."
Vietnamese is the proper adjective for Vietnam.
you talk to me i love you my family i will go to school
No, old is not a proper adjective. A proper adjective is an adjective derived from a proper noun, such as Swiss cheese, Bolivian pottery, Chinese silk, etc.
The proper adjective for George is Georgian.
Mayan is itself a proper adjective.
The proper adjective for Siam is Siamese.