Language defines thought, and cultures have asserted their identity through language. Borders in Europe, and in most parts of the world, follow linguistic dictates.
There is a serious agitation going on in the hills of Darjeeling currently. Although there are many reasons for the agitation, language, and imposition of it plays a big role.
Mamata Banerjee’s government seeks to impose Bengali, by making it compulsory in schools, including in areas which fall under the proposed Gorkhaland. This is unacceptable to the Gorkhas who are asking for a separate state of Gorkhaland.