Central Tibetan language, also known as or Ü-Tsang dialect, Dbus Tibetan, or Ü Tibetan, is the most widely spoken Tibetic language and the basis of Standard Tibetan.
Dbus is the Wylie spelling of the name in Tibetan script, དབུས་, whereas Ü is the pronunciation of the same in Lhasa dialect, [wy˧˥˧ʔ] (or [y˧˥˧ʔ]). All of these names are frequently applied specifically to the prestige dialect of Lhasa.
Amdo Tibetan (Tibetan script: ཨ་མདོའི་སྐད་, Wylie: A-mdo’i skad, Lhasa dialect: [ámtokɛ́ʔ]; also called Am kä), or Amdo dialect is the Tibetic language spoken in Amdo (now mostly in Qinghai, some in Ngawa and Gannan). It has two varieties, the farmer dialects and the nomad dialects.
Amdo is one of the three branches of traditional classification of Tibetic languages (the other two being Khams Tibetan and Ü-Tsang Tibetan). In terms of mutual intelligibility, Amdo speakers cannot communicate even at a basic level with the Ü-Tsang branch (including Lhasa Tibetan).
Lhasa Tibetan or Standard Tibetan is a standardized dialect of Tibetan spoken by the people of Lhasa, the capital of the Tibetan Autonomous Region. It is an official language of the Tibet Autonomous Region.
In the traditional "three-branched" classification of the Tibetic languages, the Lhasa dialect belongs to the Central Tibetan branch (the other two being Khams Tibetan and Amdo Tibetan). In terms of mutual intelligibility, speakers of Khams Tibetan are able to communicate at a basic level with Lhasa Tibetan, while Amdo speakers cannot. Both Lhasa Tibetan and Khams Tibetan evolved to become tonal and do not preserve the word-initial consonant clusters, which makes them very far from Classical Tibetan, especially when compared to the more conservative Amdo Tibetan.
Khams Tibetan (Tibetan: ཁམས་སྐད, Wylie: Khams skad, THL: Khamké), Kham dialect is the Tibetic language used by the majority of the people in Kham. Khams is one of the three branches of the traditional classification of Tibetic languages (the other two being Amdo Tibetan and Ü-Tsang Tibetan). In terms of mutual intelligibility, Khams could communicate at a basic level with the Ü-Tsang branch (including Lhasa Tibetan).
Both Khams Tibetan and Lhasa Tibetan evolve to not preserve the word-initial consonant clusters, which makes them very far from Classical Tibetan, especially when compared to the more conservative Amdo Tibetan. Also, Kham and Lhasa Tibetan evolved to be tonal, which Classical Tibetan was not. Khams Tibetan has 80% lexical similarity with Central Tibetan.