Bhutan is linguistically rich with over nineteen dialects spoken in the country. The richness of the linguistic diversity can be attributed to the geographical location of the country with its high mountain passes and deep valleys. These geographical features forced the inhabitants of the country to live in isolation but also contributed to their survival. The national language is Dzongkha, the native language of the Ngalops of western Bhutan. Dzongkha literally means the language spoken in the Dzongs, massive fortresses that serve as the administrative centers and monasteries. Two other major languages are the Tshanglakha and the Lhotshamkha. Tshanglakha is the native language of the Tshanglas of eastern Bhutan while Lhotshamkha is spoken by the southern Bhutanese of Nepali origin. Other dialects spoken are Khengkha and Bumthapkha by the Khengpas and Bumthap people of Central Bhutan. Mangdepkah, which is spoken by the inhabitants of Trongsa and the Cho Cha Nga Chang Kha which is spoken by the Kurtoeps. The Sherpas, Lepchas and the Tamangs in southern Bhutan also have their own dialects. Unfortunately two dialects that are on the verge of becoming extinct are the Monkha and the Gongduepkha.