The proper noun Carolina (North and South Carolina, US states) has the adjective form Carolinian.
(This is also the noun, or demonym, usually preceded by the word North or South for those states.)
The proper adjective for the proper noun "Carolina" depends on which specific region or state you are referring to. For example, "North Carolina" would have the proper adjective "North Carolinian," while "South Carolina" would have the proper adjective "South Carolinian." These proper adjectives are used to describe people or things related to the respective regions or states of Carolina.
North Carolinian
The proper noun Carolina (North and South Carolina, US states) has the adjective form Carolinian.(This is also the noun, or demonym, usually preceded by the word North or South for those states.)
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.
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.
The proper adjective for Georgia is Georgian.