The language spoken by the early Franks is known as Old Frankish and is only attested in a few words in the Lex Salica and in personal names, and is mostly reconstructed from Old Low Franconian and loanwords in Old French and Latin. In the Low Countries it evolved into Old Dutch.
Though it lent its name to a number of widely spoken dialects in modern Germany (Ripuarian, Moselle-Franconian, Rhine-Franconian, East-Franconian, South-Franconian), France (Lorrainian) and Luxemburg (Luxembourgish) these languages are not directly related to the ancient language of the Franks.[10]
Early in their history the Salians adopted Latin as a second language, as in the case of the Ubii. South of the language border, in what became northern France (langues d'oïl), Frankish was replaced by Old French from the 8th century on. Thereafter the language border between the French and Dutch languages slowly moved north to its current location.
There is no surviving work of literature in the Frankish language and perhaps no such works ever existed. Latin was the written language of Gaul before and during the Frankish period. Of the Gallic works which survive, there are a few chronicles, many hagiographies and saints' lives, and a small corpus of poems.
The word Frank has the meaning of "free" (e.g. English frank, frankly, franklin, or the Dutch expression "Frank en Vrij": Frank and Free). This arose because, after the conquest of Gaul, only Franks were free of taxation.[11]