الملخص

Diglossia phenomenon has attracted the attention of many linguists since long ago. This study is interested in investigating this phenomenon in religious discourse, viz .a number of Friday preachers speeches in the city of Mosul .The study provides evidence indicating the existence of the transition from Classical Arabic to the vernacular (colloquial) in several aspects of the language by analyzing a sample of preaches at various levels of language such as : lexical ,grammar, and phonology. The preachers speeches have been characterized by switching from Classical Arabic to colloquial dialect . This can be attributed to some reasons including : the transition for clarification , confirmation , telling a story or to deliver a message to a large number of audience in a simplified form of language . It has been found that preachers have transferred to colloquial Arabic for purposes of accuracy to avoid any ambiguity , explain difficult vocabulary , and provide some advice by telling proverbs.