Western Armenian is one of the two standardized forms of Modern Armenian, the other being Eastern Armenian. It is based mainly on the Constantinople Armenian dialect contrary to Eastern Armenian which is mainly based on the Yerevan Armenian dialect. Until the beginning of the 20th century, various dialects of the Western Armenian language were also spoken in the eastern regions of Western Armenia. The spoken or dialectal varieties of Western Armenian currently in use include Homshetsi, spoken by the Hemshin peoples; the dialects of Armenians of Kessab, Latakia and Jisr al-Shughur of Syria, Anjar of Lebanon, and Istanbul and Vaiıfli.
The Sasun and Mush dialect is also spoken in modern day Armenia villages such as Bazmaberd and Sasnashen.
Forms of the Karin dialect of Western Armenian are spoken by several hundred thousand people in Northern part of Armenia, mostly in Gyumri, Artik, Akhuryan, and around 130 villages in the Shirak province, and by Armenians in Samtskhe-Javakheti province of Georgia (Akhalkalak). As a diasporic language, and as a language that is not an official language of any state, Western Armenian faces extinction as its native speakers lose fluency in Western Armenian amid pressures to assimilate into their host countries. Estimates place the number of fluent speakers of Western Armenian outside Armenia and Georgia at less than one million.
Western Armenian is an Indo-European language. Eastern Armenian and Western Armenian are, for the most part, mutually intelligible for educated or literate users of the other, while illiterate or semi literate users of lower registers of each one may have difficulty understanding the other variant.
One phonological difference is that voiced stops in Eastern Armenian are voiceless in Western Armenian.