The Spanish adjective caribeños is different
Ordinarily it's really easy to translate adjectives of nationality (known as gentilicios in Spanish) from Spanish into English. For example:
mexicanos = Mexicans
guatemaltecos = Guatemalans
nicaragüenses = Nicaraguans
salvadoreños = Salvadorans
uruguayos = Uruguayans
chilenos = Chileans
venezolanos = Venezuelans
cubanos = Cubans
puertorriqueños = Puerto Ricans
dominicanos = Dominicans
hondureños = Hondurans
latinoamericanos = Latin Americans
But watch what happens when the adjective is caribeños. You can't refer to a group of caribeños as "Caribbeans" in English. Instead, you have to call them "residents of the Caribbean" or "people from the Caribbean" or maybe even "Caribbean dwellers."
And the adjective españoles doesn't follow the above pattern either. People from Spain are obviously called "Spaniards" in English.