United States is commonly used as a noun, but it can function as an adjective. For example:
The Unites States Navy (describing which Navy)
The United States border (specificing which border)
Vietnamese is the proper adjective for Vietnam.
The proper adjective for the proper noun 'Celt' is Celtic.Please note that a proper noun and a proper adjective is always capitalized.
Ghanian is the proper adjective for Ghana.
Since spice isn't a proper noun, it can't have a proper adjective. The adjective of spice is spicy.
Since writer is not a proper noun, it doesn't have a proper adjective.
northamerican
because United states :Unites
It depends on what unites states you speak of.
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.
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 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.
The proper adjective for Georgia is Georgian.
The proper adjective for George is Georgian.