The Systematic and Non-Systematic Substitution of the (Tāʾ) Sound in Arabi :A Descriptive and Analytical Study

This research belongs to the field of descriptive linguistic studies and seeks to explore the substitution of the (Tāʾ) sound as a prominent linguistic phenomenon in Arabic. It examines the phonetic alterations that occur between the (Tāʾ) sound and the following sounds: Wāw, Yāʾ, Sīn, Dāl, Ṣād, Ṭāʾ, Bāʾ, Thāʾ, and Hāʾ. The study aims to enhance the understanding of linguistic structures in the patterns and words where these specific substitutions involving the (Tāʾ) sound have occurred, thereby providing a detailed examination of this phenomenon. The research investigates the systematic and non-systematic phonetic substitutions of the (Tāʾ) sound, identifying which substitutions are consistent and measurable and which are attributed to dialectal variations among some Arab tribes as non-systematic substitutions. The study presents these phonetic substitutions through a structured analysis of the interactions between the (Tāʾ) sound and the aforementioned Nine sounds, categorizing them into systematic and non-systematic substitutions. It evaluates the validity of this categorization based on the actual occurrences of these substitutions. The analysis draws on classical linguistic sources that documented the substitution patterns of the (Tāʾ) sound in Arabic, their causes, and modern linguistic sources that examined the phenomenon from a contemporary linguistic perspective, validating or rejecting its occurrence. The research employs the descriptive-analytical method to achieve its objectives.The study concludes with several findings, the most prominent of which is that the substitution occurred between the (Tāʾ) sound and the listed sounds both systematically and non-systematically, necessitating a reevaluation of some aspects related to this substitution and its presence in the Arabic language.