The quadriliteral verbs in Arabic established a system, which compared to the triliteral verbs, add a new dimension and flexibility to the speakers of Arabic and facilitate meeting the daily demands of modern era for new modes of expression. The basic function of the expansions into quadrilateral verbs is to indicate intensity or repetition of the ideas denoted by the bi-radical or by the triradical verbs. This study attempts to explore the procedures of the formation of quadrilateral verbs in Iraqi spoken Arabic, taking into consideration that most Semitic verb roots are triradicals and Arabic is no exception. The author gathered the basic materials from Iraqi spoken Arabic dictionaries, Iraqi folk and children songs, Iraqi proverbs, folktales and poetry, and studies on quadriliteral verbs. He also noted examples of quadriliteral verbs spoken in Kuwait, Syria and Lebanon, United Arab Emirates and Saudi Arabia and discussed his findings with natives from different parts of Iraq. He substantiated the meaning of some of these verbs by referring to classical Arabic, Aramaic, Syriac, Hebrew, and borrowed lexical items from Persian, Turkish and Romance languages. There is no guarantee, however, that all these quadriliteral verbs are still in use, but the attempt here is to illustrates a principle, or a tendency in innovation with such verbs. The work contains three appendixes. Each one represents a different procedure in creating these quadrilateral verbs and their meanings.