This paper discusses some of the most hotly debated topics over the past few years on syntactic-semantic change in a functional-cognitive perspective and proposes a new model of grammatical change in Chinese by providing more solidly-based definitions of such notions as"grammaticalization", "lexicalization", "degrammaticalization", "exaptation" "reanalysis", and "analogy" with respect to internal processes of change as well as external ones, specifically, borrowing through language contact or contact-induced change. It will be proposed that this model is constituted by just two internal mechanisms: reanalysis and analogy. Consequently, will be argued that grammaticalization - which has been by far the focus of most of the studies on historical grammar in recent decades is secondary. The processes of grammaticalization, lexicalization and exaptation will thus be viewed as sub-classes of reanalysis, while some "degrammaticalization"/lexicalization processes will be more aptly viewed as a sub-class of analogy. The main motivations (if not genuine explanations) for grammatical change will also be discussed, i.e. semantic-pragmatic change, including mainly metaphorical extension, pragmatic inferencing or metonymization and (inter-) subjectification, as well as others, such as phonological change. Concerning the third- and external- mechanism of change, it will be shown that the several universals and principles of borrowing that have been proposed remain rather ill-defined.