Referential relations are expressed by demonstratives, possessive pronouns, or by numerals expressing indefinite reference, etc. The definite reference realized by the demonstrative 那（座）‘nà (zuò)’ (that) in the expression 那座房子‘nà zuò fángzi’ (that house), is crucially sensitive to the context, too. The choice of the definite reference reflects the speaker’s belief or assumption that the house is identifiable or known to the hearer in the context. If the speaker assumes that the referent is unidentifiable to the hearer in a certain context, or the identification of the referent is irrelevant or trivial to the hearer, the NP may take a corresponding form, either by the number ‘yī’ (a, one) for indefinite reference, or by the nonreferential form: bare NP, as in 张三在写一本书。‘Zhāng Sān zài xiě yī běn shū’ or 张三在写书。‘Zhāng Sān zài xiě shū’ (Zhang San is writing a book). Therefore referential relations are pragmatic, as the identification of referent must be associated to some entity in the context.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.