Grabar meaning "literary," Armenian was very developed by the time it came to be written down at the beginning of the 5th century. All early Armenian literature, through the 18th century, is in the Grabar Armenian language. Knowledge of the language is therefore a prerequisite for the study of the Armenian literary heritage, and for its ancient manuscripts. Also many ancient Greek, Persian, Hebrew, Syrian and Latin manuscripts survive only in their Armenian translation. Classical Armenian continues to be the liturgical language of the Armenian Apostolic Church. Moreover, Biblical, Intertestamental , and Patristic scholars dedicated to textual studies are often prone to learn Grabar. Also, this ancient language has long attracted the attention of linguists studying the roots of Proto-Indo-European language, for the majority of whom it is essential for the subject.