This analysis includes a description of language-contact phenomena such as stratification, hybridization, and convergence for Sinitic languages. It also presents typologically unusual grammatical features for Sinitic such as double-patient constructions, negative existential constructions and agentive adversative pass ives, while tracing the development of complementizers and diminutives and demarcating the extent of their use across Sinitic and the Sinospheric zone. Both these kinds of data are then used to explore the issue of the adequacy of the comparative method to model linguistic relationships inside and outside the Sinitic family. It is argued that any adequate explanation of language family formation and development needs to take into account these different kinds of evidence (or counter-evidence) in modelling genetic relationships.