This research handles one of the issues of the phonological research in the book "Al-Bayan fi Gharib I'rab Al-Qur'an" by Abu Al-Barakat bin Al-Anbari (d.577 AH); namely, the issue of phoneme substitution which was so numerous in that book in a prominent way relative to the other phonologicak issues handled therein.The research came in an Introduction in which the researcher handled the interest of...