It is well observed that head licensing is crucial in VP movement and ellipsis. However, a closer investigation into (pre-verbal) aspectual elements in Mandarin and Cantonese reveals that not all head elements successfully license VP movement and ellipsis. This paper examines (im)perfective markers and aspectual verbs and their ability to license VP movement and ellipsis in these languages. It is shown that only a subset of them are proper head licensors. The split observed within aspectual elements calls for a more fine-grained formulation of the licensing conditions of VP movement and ellipsis in Mandarin and Cantonese. In tandem with a contextual/dynamic approach to phasehood, it is proposed that phases are privileged in the sense that the verbal phrases that can undergo VP movement and ellipsis must be a phase in these languages. The proposal implicates (i) that the boundary of the clause-internal phase is not determined categorically, but displays certain flexibility depending on syntactic environments, and (ii) that the low aspect projection has a unique status in setting the upper boundary of the clause-internal phases.