This contribution concerns the functioning of languages in one of the genre of commercial display, namely that of commercial signs, in the multilingual and historically Berber-speaking context of the city of Batna, in Algeria. In terms of the languages displayed, the study highlights in particular the preponderant place, both in unilingual and bi-plurilingual signs, occupied by the French language, institutionally declared a foreign language in Algeria, compared to those occupied by standard Arabic and by local mother tongues, dialectal Arabic and Berber. It highlights the use by sign designers of other foreign languages such as English, Italian, etc. Finally, it shows the different ways in which languages mingle with each other, namely : translation, transliteration and intraphrastic alternation.