Switzerland has four national languages, but they vary greatly in the number of speakers.
German is by far the most widely spoken language in Switzerland: 17 of the 26 cantons are monolingual in German.
French is spoken in the western part of the country, the "Suisse Romande." Four cantons are French-speaking: Geneva, Jura, Neuchâtel and Vaud. Three cantons are bilingual: in Bern, Fribourg and Valais both French and German are spoken.
Italian is spoken in Ticino and four southern valleys of Canton Graubünden.
Rumantsch is spoken in the only trilingual canton, Graubünden. The other two languages spoken there are German and Italian. Rumantsch, like Italian and French, is a language with Latin roots. It is spoken by just 0.5% of the total Swiss population.
The language spoken in German-speaking Switzerland is quite different from standard German - called High German. The German Swiss speak Swiss German, often called "Mundart" - which itself is broken up into numerous local dialects
German 63.7%
French 20.4%
Italian 6.5%
Rumantsch 0.5%
Other 9 %
(www.swissword.org - popolazione - lingue)