The purpose of this study is to investigate the prefixes that are used in the urban dialect of Gaza cities and are attached to the imperfect verbs to identify the tense: present simple, present continuous, future and conditional sentences. Another aim is to figure out the varieties of these prefixes that are used in the urban dialect of Gaza cities. Finally, concerning this morphological aspect, to which Arabic dialect group that the urban dialect of Gaza belongs to, is examined as well in this study. Quantitative research methodology is utilized in this study. The quantitative research data was gathered from Al-Aqsa Radio Station, broadcasted from Gaza Strip. The total hours recorded are 19 hours; the data is collected from programs that depend on audience participation via the telephone, guests in the studio and radio correspondents? interviews with people in Gaza.