Shí yuè yī rì Guóqìngjié.
(October First is the National Day.)
Wáng lǎoshī Běijīngrén.
(Teacher Wang is from Beijing.)
Each sentence above is composed of two NPs. For the two NPs to form a sentence expressing a proposition, they must be considered to be in the topic comment construction. The first NP, which is definite or generic expressing given information, serves as the topic, representing a referent ‘identifiable’ and ‘of current interest’ to the hearer; while the second NP must be able to be construed as conveying some information that is ‘about’ or ‘relevant’ to this topic in the context of the speech situation. Thus a ‘topic of’ relation is established between the first and the second NPs. For instance in (2a), the initial NP ‘shí yuè yī rì’ (October the first) refers to a date, and the second NP ‘Guóqìngjié’ (national Day) represents a holiday. From our world knowledge, we know that a festival or holiday is related to a date, therefore, the information conveyed by the second NP can be construed as relevant to the first NP. Hence, the two NPs form a meaningful proposition: October first is the national holiday. A similar explanation carries over to (1b). This type of construction is quite common in Chinese and is thus known as the nominal predicate construction, since the second NP plays the role as that of the predicate, namely expressing a proposition about the first topic NP.
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles.
New York: Peter Lang.