This paper deals with the rise of the grammatical elements of simple future in the Nile Nubian languages (i.e., Kenzi and Fadicca) and Arabic (i.e., Standard Arabic and Cairene Colloquial Arabic). Using grammaticalization as a frame of reference, I attempt to determine the sources, the mechanisms and processes involved in the development of the grammatical elements in these languages. In addition, the study sheds light on the points of similarity and difference between these languages as far as the rise of future expression is concerned.