Oirat language in the context of "Four Oirats"

The traditional Mongolian script, also known as the Hudum Mongol bichig, was the first writing system created specifically for the Mongolian language, and was the most widespread until the introduction of Cyrillic in 1946. It is traditionally written in vertical lines from top to bottom, flowing in lines from left to right . Derived from the Old Uyghur alphabet, it is a true alphabet, with separate letters for consonants and vowels. It has been adapted for such languages as Oirat and Manchu. Alphabets based on this classical vertical script continue to be used in Mongolia and Inner Mongolia to write Mongolian, Xibe and, experimentally, Evenki.

Qinghai is an inland province in Northwestern China. It is the largest province of China (excluding autonomous regions) by area and has the third smallest population with its capital and largest city being Xining.

Qinghai borders Gansu on the northeast, Xinjiang on the northwest, Sichuan on the southeast and the Tibet Autonomous Region on the southwest. Qinghai province was established in 1928 during the period of the Republic of China, and until 1949 was ruled by Chinese Muslim warlords known as the Ma clique. The Chinese name "Qinghai" is after Qinghai Lake, the largest lake in China. The lake is known as Tso ngon in Tibetan, and as Kokonor Lake in English, derived from the Mongol Oirat name for Qinghai Lake. Both Tso ngon and Kokonor are names found in historic documents to describe the region.

Kalmyk Oirat (Хальмг Өөрдин келн, IPA: [xalʲmə́k ɵːrd̥íɴ kʰelə́ɴ]), also known as the Kalmyk language (Хальмг келн) and formerly anglicized as Calmuck, is a variety of the Oirat language, natively spoken by the Kalmyk people of Kalmykia, a federal subject of Russia. In Russia, it is the standard form of the Oirat Mongolian (based on the Torgut dialect), which belongs to the Mongolic language family. The Kalmyk people of the Northwest Caspian Sea of Russia claim descent from the Oirats from Eurasia, who have also historically settled in Mongolia and Northwest China. According to UNESCO, the language is "definitely endangered". According to the Russian census of 2021, there are 110,000 speakers out of an ethnic population consisting of 178,000 people.

The Khalkha dialect is a dialect of central Mongolian widely spoken in Mongolia. According to some classifications, the Khalkha dialect includes Inner Mongolian varieties such as Shiliin gol, Ulaanchab and Sönid. As it was the basis for the Cyrillic orthography of Mongolian, it is de facto the national language of Mongolia. The name of the dialect is related to the name of the Khalkha Mongols and the Khalkha River.

There are certain differences between normative (standardised form of Khalkha) and spoken Khalkha. For example, the normative language uses proximal demonstratives based on the word stem ʉː/n- (except for the nominative in [i̠n] and the accusative which takes the stem ʉːn-) and thus exhibits the same developmental tendency as exhibited by Oirat. On the other hand, the spoken language also makes use of paradigms that are based on the stems inʉːn- and inĕn-. This seems to agree with the use in Chakhar Mongolian. The same holds for the distal demonstrative /tir/.

The Clear Script is an alphabet created in 1648 by the Oirat Lamaist monk Zaya Pandita for the Oirat language. It was developed on the basis of the Mongolian script with the goal of distinguishing all sounds in the spoken language, and to make it easier to transcribe Sanskrit and the Tibetic languages.

Torgut (Oirat: Торһд, romanized: Torhd, [torˈɣət]), also spelled Torghud, is a dialect of the Oirat language spoken in Xinjiang, in western Mongolia and in eastern Kalmykia (where it was the basis for Kalmyk, the literary standard language of that region). Thus, it has more speakers than any other variety of Oirat. It is better researched than any other Oirat variety spoken in China.