Abstract
This study deals with the phenomenon of the relational adjective in Mostafa Saadeq Al-Rafe'ie’s book (Inspired Pen), and shedding light on the related issues. This book was selected because of its great significance in the field of the nation's life and the thought in the modern era. It also represents Al-Rafe'ie’s effort and his art in the interweaving Arabic Language Systems as well as the book is rich in its material of the morphological application. Al-Rafe'ie used the relational adjective with stressed (ya') and morphological formats. The Arabs amended in some places from relational adjective with stressed (ya') using (faa'l), (fae'l) and (fe'l). Each formula indicates various meanings before determining meaning by evidences. Al-Rafe'ie also dealt with the irregular relational adjective of the morphological principle in some of his articles.