Despite the amount of material about Arabic grammar, phonology, and morphology, the need for a book combining an independent study in morphology with theoretical discussions is more than evident. This book fills that void by proposing an in-depth analysis of various morphological issues based on the seven classes of verbs and their nine derivatives. These classical classes are the strong verb, the doubled, the hamzated, the verb with 1st radical w or y, the verb with 2nd radical w or y, the verb with 3rd radical w or y, and the verb that is doubly weak. The nine derivatives are the perfect, imperfect, imperative, infinitive noun, active participle, passive participle, noun of time, noun of place and noun of instrument. The different sections introduce several paradigms of verbs, a carefully explored data and explicit information about the morphological structures and the various phonological changes that can affect them, such as the addition, transfer or elision of a vowel or letter, the assimilation of two letters and the substitution of one letter for another. The study pays also particular attention to the most representative works from the 8th century until our days.