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.
The proper noun for the proper adjective Taiwanese is Taiwan.
Yes, Taiwan is a proper noun. It refers to a specific country in Asia.
The word Taiwan is the proper noun. a proper noun is always capitalized.
The proper adjective for southwest is "southwestern."
The proper adjective is Haitian.
The proper adjective for Portuguese is "Portuguese."
Chinese is the adjective form of the proper noun China. For other uses, 'Sinic' is the word you're looking for, as in "Sinic customs are different from those of Japan". The prefix derived from that is 'sino' as in the phrase "Sino-Indian border".
Vietnamese is the proper adjective for Vietnam.
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.