Puerto Rico is an Unincorporated Territory of the United States, and before being subject to United States ownership, Spain maintained control of the island. Due to its history, Puerto Rico has a largely hispanic culture, and the native language of Puerto Rico is Spanish. In fact, despite English being taught all throughout primary schooling, no more than 20% of Puerto Ricans speak fluent English. (1, welcometopuertorico.org) The official languages of Puerto Rico are Spanish and English.
Puerto Rico is not a part of the UN, IMF, or WHO, but the United States is, and Puerto Rico is United States territory.