This study investigates the diachronic drift of Arabic future-marking parti cles, empirically testing the shift from synthetic (سـ, سوف) to analytic (راح, قاعد+ح) forms across registers and regions. Leveraging a multi-register corpus (Penn Arabic Treebank, Corpus of Contemporary Arabic, Arabic Gigaword Fifth Edition) and advanced NLP tools (MADA, CAMeL Tools, AraBERT), we extracted and analyzed future-marker tokens annotated for register (newswire, opinion, social media, religious), region (EG, SA, LB, MA), and time slice (1990-2000, 2000-2010, 2010-2023). Mixed-effects logistic regression revealed significant effects of time, register, and region, confirming a clear diachronic shift towards analytic markers, particularly راح and قاعد+ح. Interaction terms highlighted that this shift is more pronounced in informal registers and certain regions, indicating dialectal pressure and diffusion of innovations (e.g., Gulf Arabic راح) into broader usage. Hierarchical clustering of contextual embeddings would further validate semantic-pragmatic shifts. This research provides robust evidence for ongoing linguistic change in Arabic, contributing to theories of grammaticalization and language contact.