On the hierarchy of structural convergence in the Amdo Sprachbund
The languages of the Amdo region in the Sino-Tibetan borderzone form an areal union of the Sprachbund type, in which all participants have been approaching a common goal of structural uniformity. There are, however, differences as to how the goal of uniformity has been achieved in each given language. Some structural features seem to be easily lost or borrowed, while others are more stable and language-specific. Observations made of the Amdo Sprachbund confirm results obtained in other parts of the world concerning the stability of features like ergative and nominal phrase word order. On the other hand, the universally rare category of perspective, present in several languages of the Amdo region, seems to be easily transferred from one language to another.