This paper provides an analysis of Al-ibdaal ‘substitution’ phenomenon found in Modern Standard Arabic (MSA) derivational processes, particularly, in the pattern ftaʕal. Al-ibdaal ‘substitution’ is defined in many Arabic morphological books (Al-Raagihi, 1984; Al-Galaayiini, 1991) as removing a letter and replacing it by another. For example, the /t/ in ztaha: is replaced by /d/ resulting in zdaha: ‘flourished’. The paper analyzed examples of words representing the pattern ftaʕal based on prosodic morphology; an approach used to describe non-concatenative morphological processes as those found in Arabic and other Semitic languages (McCarthy, 1981). The analysis of the words revealed that there is actually no substitution of sounds and the change that takes place in that pattern is phonologically motivated. The paper recommends the reconsideration of the concept of Al-ibdaal ‘substitution’ in the pattern ftaʕal in Arabic morphological books
Keywords: Arabic Morphology, Morphophonology, Phonology, Prosodic Morphology, Substitution
