This paper presents the analysis of a common feature in Late Egyptian and Biblical Hebrew verbal systems, namely the existence of sequential forms, used to coordinate two sentences sharing the same time reference. This feature is analyzed both synchron ically and diachronically, whereby it appears that sequentiality is not a distinctive element of Egyptian and Semitic throughout their linguistic development, but a charac teristic of that area of Afroasiatic in one definite period of time. The formation of a new verbal paradigm containing sequential forms is tentatively interpreted within the general perspective of the creation of conjugated forms which supersede, in Late Egyp tian (plus Demotic and Coptic) and Biblical Hebrew (plus the post - Biblical language) the old formations, where differences in vocalic patterns indicated morphological varieties (Middle Egyptian sdm.f and Proto - Semitic / Ugaritic.