Pragmatics is primarily concerned with context and use. Pragmatic relations include implicature, inference, topic, old-new information, referential relations, foreground and background information, etc. All these relations are dependent on context and the speaker’s attitude, but have little to do with the head word. Therefore, pragmatic relations are basically structure-external and discourse-oriented. Pragmatic relations may reflect a linguistic unit’s association with an entity in the context, such as a definite or indefinite reference. They are also a manifestation of how the speaker uses or handles a specific linguistic unit. For instance, the speaker’s choice of a topic and his selection of a part of linguistic unit as an information focus to highlight. In short, pragmatic relations involves the speaker’s assumptions and attitude, they are essentially sensitive to context. Therefore, pragmatic relations are temporary, unstable, and changeable with different contexts (Lu, 1998).
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.