This volume thoroughly analyzes the phonology of a representative dialect of Moroccan Arabic (MA). This dialect is phonologically interesting because of the existence of numerous productive patterns of derivational ablaut, several types of play speech transformation, and various problems in representation of stems and formalization of rules due to the progressive reduction or disappearance of older short vowels. In examing ablaut, Heath formally models all productive derivational patterns using concepts of mapping and projection from input stems onto output stems, and not making use of abstract "root" representations. The formal details of mapping and projection differ significantly from one pattern to another (several use a bidirectional, i.e., periphery-in, strategy), and each pattern has various idiosyncratic accessory rules. Data from ablaut, play speech, and borrowings are also used extensively to discuss syncope vs. epenthesis analyses of short vowel; short u vs. recognition of labialized consonants kwgwqwxwgw; behavior of geminates; syllabification of sonorants in long consonantal strings; hiatus; and, pharyngealization ("emphasis"). The volume combines descriptive thoroughness and formal rigor with a sensitivity toward unsettled areas in the phonology--structural conflicts, pragmatic aspects of stem representation, and gradually evolving restructurings of the system.