The file contains metadata on 22500 negative sentences from 1046 Italo-, Gallo-, and Rhaeto-Romance dialects. It is based on primary data from the Atlas linguistique de la France (ALF; Gilliéron and Edmont 1902-1910) and the Sprach- und Sachatlas Italiens und der Südschweiz (AIS; Jaberg and Jud 1928-1940). This dataset is a research output of the project Coding Syntactic Microvariation (CoSMic), funded by the IDEX programme of the Université Côte d'Azur (CSI Recherche 2021). This file is shared under the Creative Commons Attribution CC BY-NC-SA license.