Slovenian language or Slovene language is a South Slavic language which is written in roman alphabet. South Slavic languages belong to the Balto-Slavic branch of the Indo-European language family. It is widely spoken in Slovenia and in adjacent parts of Austria and Italy. Slovenian language has great dialectal variations. It has native speakers around 2.5 million. It is also spoken by Slovene national minorities Friuli-Venezia-Giulia. It is considered the most diverse Slavic language in terms of dialects. Slovenian is closely related to Chakavian dialect of Serbo-Croation. This language shares certain linguistic characteristics with all the other south Slavic languages including those of the Eastern subgroup. Slovenian traces its roots to the proto-Slavic group of languages which produced the old church Slavonic. It consists of 21 consonants and 8 vowels. It has T-V distinction just like most other European languages. Slovenian has dual grammatical form; this is categorized as the most distinctive character of the language. The Freising manuscripts are the oldest given Slovenian documents which were written in 9^th century. It is known as one of the rarest languages of the European union.