The position of the word final –s, after a weakening in archaic Latin, seems to be fixed in the spoken language in the classical period. Then, it partially disappeared in the Romance languages: in modern languages, it is conserved only north and west of the Massa–Senigallia line, while we cannot find it neither in the eastern regions nor in South Italy. Based on this fact, linguists generally claim that the weakening of the final –s started only after the intensive dialectal diversification of Latin, simultaneously with the evolution of the Romance languages. However, the data of the Computerized Historical Linguistic Database of Latin Inscriptions of the Imperial Age (LLDB) do not verify this generally accepted opinion. We can find almost as many examples of the lack of word final –s as that of –m also from the earlier centuries of the Imperial age. The aim of this paper is to explore the reasons behind the inconsistencies between the scholarly consensus and the epigraphical data.