Coptic or Coptic Egyptian (Bohairic: met.rem.ən.khēmi, Sahidic: mənt.rəm.ən.kēme, Greek: Met Rem(e)nkhēmi) is the latest stage of the Egyptian language, a northern Afro-Asiatic language spoken in Egypt until at least the 17th century. Egyptian began to be written in the Coptic alphabet – an adaptation of the Greek script with some letters inherited from Demotic – in the 1st century CE. The new writing system became the Coptic script, an adapted Greek alphabet with the addition of six or seven signs from the demotic script to represent Egyptian sounds the Greek language did not have. Several distinct Coptic dialects are identified, the most prominent of which are Sahidic, originating in parts of Upper Egypt, and Bohairic, originally from the western Nile Delta in Lower Egypt. Coptic and Demotic Egyptian are grammatically closely akin to Late Egyptian, which was written in the Hieroglyphic script. Coptic flourished as a literary language from the 2nd to 13th centuries, and its Bohairic dialect continues to be the liturgical language of the Coptic Orthodox Church of Alexandria. It was supplanted by Egyptian Arabic as a spoken language toward the early modern period, though revitalization efforts have been underway since the 19th century.