In order to state general rules about the construction of a sentence, we must constantly refer to units smaller than the sentence itself. These units are clause elements of which a clause or a sentence is composed. Generally, discussion of word order in a language tends to revolve around the ordering of clause elements: subject, verb, object, complement and adverbial, among these elements, the verb is considered the nucleus (Quirk, et. al. 1985).
 Loar, J. K. (2011). Chinese syntactic grammar: functional and conceptual principles. New York: Peter Lang.