Southern Mongolian or Inner Mongolian (Mongolian: ᠥᠪᠦᠷ ᠮᠣᠩᠭᠣᠯ ᠠᠶᠠᠯᠭᠣ Öbör mongγol ayalγu) is a proposed major dialect group within the taxonomy of the Mongolian language. It is assumed by most Inner Mongolian linguists and would be on the same level as the other three major dialect groups Khalkha, Buryat, Oirat. (Within this classificational scheme, Oirat usually includes Kalmyk, but a classification that assumes Kalmyk as a major dialect group of its own right also exists.) Southern Mongolian would consist of the dialects Chakhar, Ordos, Baarin, Khorchin, Kharchin and (possibly) Alasha that originated from Oirat. The varieties spoken in Xilin Gol which form a major dialect of their own right and are close to Khalkha are classified as belonging to Chakhar in this approach. Because Southern Mongolian would consist of all non-Buryat Mongolian varieties spoken in Inner Mongolia, this classification has been argued against by several linguists who hold that there is a dialect continuum between Khalkha and the Southern Mongolian varieties that rather favours grouping Chakhar, Ordos and Khalkha on the one hand and Khorchin and Kharchin on the other hand, or at least that "Mongolian proper" is an immediate member of Mongolian/Mongolic. On the other hand, the argument that Southern Mongolian is distinct is based on considerations such as the following:
Given its intended status that was formally implemented and delimited at a conference in Ürümqi in 1979, Southern Mongolian has been the object of several grammars. This includes an eclectic grammar that specifically deals with normative spoken language and which is based on the Chakhar dialect as spoken in the Plain Blue Banner on which the normative Southern Mongolian pronunciation Standard sounds (Mongolian: ᠪᠠᠷᠢᠮᠵᠢᠶᠠ ᠠᠪᠢᠶᠠ barimǰiy-a abiy-a) is based. But legally, the grammar of all Southern Mongolian dialects jointly provides the standard grammar. This is still a delimitation, as Buryat and Oirat speakers in China are obliged to use Southern Mongolian as their standard variety as well. To work as a school teacher, news anchor etc., a special command of Southern Mongolian is required and tested. The test manual focuses mainly on pronunciation, but to some degree also on vocabulary, while syntax is stated to be tested, but left to the evaluators. To teach Mongolian, a score of more than 90% is needed, while teachers of other subjects are only required to obtain 80%, the minimum score for successful completion.