Complex sentence: The Fascist regime accused the Swiss government of oppressing the Romansch people in Graubünden, the Swiss government responded to the Italian threat to Switzerland's territorial integrity by establishing Romansch as a "national language" but not an official language, in February 1938.
Split into simpler sentences: The Fascist regime accused the Swiss government of oppressing the Romansch people in Graubünden. The Swiss government responded to the Italian threat to Switzerland's territorial integrity by establishing Romansch as a "national language" but not an official language, in February 1938.