Both sentential final particles (SFPs) and high modals commonly convey the speakers’ knowledge of the world, their judgments, intentions, and subjective attitudes. This paper aims to explore the correlations between high modals and sentence-final particles in Mandarin Chinese (MC). Specifically, two high modals of MC show the behavior of being unable to precede the subject and eliminating their epistemic reading in the presence of SFPs. The phenomenon discussed in this paper is specifically exemplified with