Abstract
At a very early date، the Arab grammarians invented a notation for the morphological patterns التصريف which represented the three root radicals فعل For those grammarians، the task of morphology was the breakdown of words into radical and auxiliary .الزوائد consonants The grammarians set up methods to identify the radicals، of which the most important was الاشتقاق 1 ، the comparison of the form under scrutiny with morphologically-related words with the same semantic content. In line with the idea of the purity of the language، the semantic extension of an existing word was regarded as the most appropriate device for expansion of the lexicon. The model for this procedure was believed to have been given by the language of the Qur'an itself. Semantic extension became an accepted method of creating new terminology. It has two most important kinds، that are: • Ishtiqaq al Sagheer ، it generates the words from the same root. • Ishtiqaq al Kabeer ، it generates the words from the rotation of the verb. The most important outcome of this research is as follows: Morphological derivatives help in generating lexical words and semantic meanings