The city of Berne [bɜːn](UK), [bɝːn](US) (German: Bern [b̥ɛrn], French: Berne [bɛʀn], Italian: Berna [ˈbɛrna], Romansh: Berna [ˈbɛrnə], Bernese German: Bärn [b̥æːrn]), is the Bundesstadt (federal city, de facto capital) of Switzerland and, with 140,000 people, is the fourth most populous city in Switzerland (after Zürich, Geneva and Basel). Most of Berne's residents speak German, or more specifically, Bernese German, which is a high-Alemannic dialect. The Canton of Berne has a French-speaking part. Very few people still speak the Mattenenglisch, a language game used in the former workers' quarter of Matte, but several words have found their way into Bernese German. Berne also functions as the capital of the Canton of Berne, the second most populous of Switzerland's cantons. Illustrious Bernese include the reformer Albrecht von Haller, the poet Albert Bitzius and the painters Hans Fries, Ferdinand Hodler and Paul Klee. The German-born physicist Albert Einstein worked out his theory of relativity while employed as a clerk at the Berne patent office. A culturally important person was Mani Matter, a songwriter performing in Bernese German.