Acquisition of Arabic Verb Morphology by Yoruba L1 Speakers: A Developmental Sequence Study

Verb morphology constitutes one of the most complex and acquisition-sensitive domains of Arabic grammar, and the developmental sequences through which Yoruba L1 speakers acquire Arabic verb forms have not previously been charted in longitudinal research, leaving Arabic teachers working with Yoruba-speaking Nigerian students without empirically grounded expectations for morphological development stages. This study investigates the developmental sequence of Arabic verb morphology acquisition by Yoruba L1 speakers enrolled in Arabic language programmes in three universities in Oyo and Osun States. Using a longitudinal morphological assessment methodology, the research tracks 80 Yoruba L1 Arabic learners from entry to their third year of university Arabic study, administering morphological elicitation tasks at four time points covering present and past tense conjugation, derived form recognition and production, and morphological decomposition in novel words. Cross-sectional data from 40 advanced learners is used to project developmental endpoints. The developmental sequence is compared with sequence predictions derived from Universal Grammar hypotheses and processing complexity models of morphological development. The study identifies a clear developmental ordering in which root-pattern awareness precedes productive derivational morphology, and in which agreement morphology develops significantly later than paradigmatic inflection for most learners. Yoruba transfer effects are documented in vowel quality errors in particular morphological environments. Keywords: Arabic verb morphology, acquisition sequence, Yoruba L1, developmental stages, morphological development.