The diachronic description of a language is not complete unless one considers the linguistic substrata and adstrata spoken beforehand by a population that then came to coexist with the language in question. Thus, the fourth volume of the Encyclopédie provides a detailed description of the influence exerted by the Romance substratum and the Berber adstratum on Andalusian Arabic dialects.

The diachronic description of a language is not complete unless one considers the linguistic substrata and adstrata spoken beforehand by a population that then came to coexist with the language in question. Thus, the fourth volume of the Encyclopédie provides a detailed description of the influence exerted by the Romance substratum and the Berber adstratum on Andalusian Arabic dialects.