[1][2][3] Marchello-Nizia studied at the École normale supérieure de Fontenay-Saint Cloud, receiving her doctorate in 1975.
In 1998 she was made a Knight of the Legion of Honour for services to education, and was promoted to Officer in 2013.
[5][6] She has been a member of the Finnish Academy of Science and Letters since 2002, and was awarded an honorary doctorate by the University of Helsinki in 2003.
[2] For her two-volume historical grammar of French (Grande Grammaire Historique du Français) she and her co-authors were also awarded the 2021 Prix Honoré Chavée by the Académie des Inscriptions et Belles-Lettres.
[8] Marchello-Nizia has made contributions to research across the areas of historical linguistics, language change, historical pragmatics, diachronic syntax, grammaticalization, the history of the French language, Romance corpus linguistics, text editing, and the semiotics of medieval French texts.