Language isolates are natural languages that have no known linguistic or historical links to any other languages. By natural we mean a language that has evolved over time through repetition; unlike a constructed language, such as Esperanto. Language isolates may be classified as language families consisting of a single language or may be isolates due to the fact we know so little about them. They exist all over the world and are extremely interesting to study.
While it is possible that language isolates may take or borrow words from another language, their structure and word pool remain fundamentally dissimilar to any other language. What makes them so special is that even after considerable research, linguists and scholars have not been able to find sufficient links to other languages that exist now or ones that have become extinct. It’s clear that they didn’t spontaneously exist so the process of how the language was formed is often a mystery, how a language managed to form without strong influence from another dialect is very challenging. For a long time Japanese was considered a language isolate until detailed study showed links to various Ryukyuan languages; this relationship means it is now considered in the Japonic language family.
Below are some better known language isolates that still exist today, the most recently formed being Nicaraguan Sign Language. The only language that linguist have been able to study from the day it was created.
Korean is the most widely spoken language isolate with about 80 millions speakers world wide. It is also the only language isolate that is the official language of a country; Basque and Ainu are not the main languages of the state. There were some previous ideas on a Japanese Korean link but that has been discredited by most scholars now so it remains the most prominent and vibrant language isolate in the world today.
The Basque language is spoken by about 580,000 (some what disputed) people in the Basque country, most of which is in Spain. It remains an isolate despite thousands of years of contact with English, Spanish and French. Although it has borrowed several words, the survival of this language as an isolate still amazes linguists; mostly due to its constant contact with many languages.
Burushaski is probably the next most spoken isolate; by a small community in northern Pakistan. There are about 87,000 speakers. This language again has survived with intense contact from other surrounding languages without taking lexical and linguistic structure from them. Burushaski is an isolate that has many borrowed words from Urdu through English but still structurally and grammatically remains independent.
Nicaraguan Sign Language
Possibly the newest language ever, Nicaraguan Sign Language was developed independently in the playground by deaf children. It was completely created from scratch and without outside influence which makes it incredibly interesting for linguist to study.
A side not: Etruscan
While this isolate is not spoken anymore, Etruscan is most famously know to be the biggest influence on Latin, a language which survived for more than a thousand years and further influenced the Romance languages such as Italian, Spanish, French and Portuguese. Due to the extinction of the Etruscan people not much is known now about the language but no prior links have been found.