Isolated languages, also known as language isolates, are languages that have no known relatives or connections to any other language. These languages have not been demonstrated to be part of any language family, making their origins and relationships with other languages a mystery to linguists. Some examples of isolated languages include Basque, Ainu, Burushaski, Nahali, and Kusunda, etc. These languages continue to puzzle linguists due to their lack of discernible relationships with other languages.