Polish
The adjective derived from the word Poland is Polish.
Polish is a proper adjective that can be used for Poland.
The adjective is variously spelled as Praguean or Praguian, often referring to the Prague School/ Prague Circle of Linguistics, rather than the city of Prague in Poland. The demonym for a resident of Prague (noun) is Praguer.
The word "Polish" (capitalized) is a proper adjective referring to something or someone from Poland. The word polish can be a verb (to clean, smooth, or shine) or a noun (a substance used to polish). The adjective would be polished or polishing.
The proper adjectives are:KoreanPolishAlaskanBelgianSwedishFrenchRussianCubanPeruvianIndian
The noun polish is a common noun, as in "I am going to use some polish." The word polish is also a verb, as in "I will polish my shoes." The noun Polish is a proper noun as a word for the language of Poland, "They speak English and Polish." A proper noun is always capitalized. As an adjective, Polish is a proper adjective as in "They are a Polish family." A proper adjective is always capitalized.
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.