Here's why:
* Proper Noun: "Polish" in this context refers to a specific culture, making it a proper noun. Proper nouns are capitalized in English.
* Nationality: It also represents the nationality of people from Poland.
* Language: "Polish" refers to the Polish language, which is also a proper noun.
Examples:
* "I'm fascinated by Polish folk music."
* "She's studying Polish history."
* "We learned about Polish culture in our class."