In contrast to English, Chinese adopts a two-step schema: First, Chinese uses the verb ‘zài’ to express the notion of existence of the located object in space; second, the reference object that the located object is spatially related to is indicated explicitly as a part or a component of the reference object. The state of affairs denoted by (1), for instance, can be paraphrased as ‘the ball exists on the top of the table’. The reference object is in fact, not the whole table, but the particular part of the table, that is the top surface of the table, and ‘shàng (bian)’ is pragmatically determined to be two dimensional. ‘shàngbian’ is called a position word in Chinese, and it is a noun.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.