Arabic Morphology (علم الصرف) is a branch of Arabic Grammar dealing with word-forms and patterns. It is highly essential for the incumbent student of Arabic to learn this science in order to be proficient in the language.
Acquiring an understanding of word patterns is of prime importance in learning the language. Arabic morphology is different from English in some very basic respects but it is highly systematic. In fact, Arabic and the Semitic languages have had substantial influence on the development of certain key concepts in theoretical morphology.
Theories of word structure or morphology, usually focus on two essential issues: how words are formed (derivational or lexical morphology) and how interact with syntax (inflectional morphology e.g, marking for cateogires such as gender, number, case and tense)
This very science discusses the change of a word into various forms in order to achieve the desired meaning. For example, the changing of صَدَقَ to صادِق.