How well do language models understand Meenzerisch, the dialect spoken in the German city of Mainz? A research team led by Johannes Gutenberg University Mainz (JGU) has now investigated this question for the first time. Meenzerisch still shapes regional language culture today and is known across Germany through the satirical carnival speeches in the famous Mainz Fastnacht tradition. The study’s findings, recently presented at the 2026 Language Resources and Evaluation Conference (LREC) in Palma de Mallorca, show that current Artificial Intelligence (AI) models have great difficulty understanding the dialect correctly.