Romansh language the most comprehensive collection of Romansh words, which can also be used in the idioms with the necessary phonetic shifts. The signatories of "Pro Rumantsch" stress that Romansh needs both the idioms and Rumantsch Grischun if it is to improve its chances in today's communication society. In Switzerland, official language use is governed by the "territorial principle": Cantonal law determines which of the four national languages enjoys official status in which part of the territory. Only the federal administration is officially quadrilingual. Romansh is an official language at the federal level, one of the three official languages of the Canton
Romansh language their regional variety. The cantonal government aimed to introduce Rumantsch Grischun as the sole language of instruction in Romansh schools by 2020. In early 2011, however, a group of opponents in the Surselva and the Engadine founded the association Pro Idioms, demanding the overturning of the government decision of 2003 and launching numerous local initiatives to return to the regional varieties as the language of instruction. In April 2011, Riein became the first municipality to vote to return to teaching in Sursilvan, followed by an additional 4 in December, and a further 10 in early 2012, including Val Müstair, which