Abstract This paper investigates the syntax and semantics of the third person singular pronoun ɦi⁶ in Shanghainese in its non-referential use. Evidence from its phonological dependence and syntactic integration with the preceding host verb is presented to show that the non-referential ɦi⁶ is a clitic. It is further observed that this use of ɦi⁶ requires licensing from the [+subjunctive] feature, echoing Qian (2004) and Jin (2016). However, my analysis diverges from theirs in treating the ɦi⁶ in question as an expletive licensed by the [+subjunctive] feature, rather than a subjunctive marker itself on grounds that it is not obligatory in a subjunctive sentence and that the subjunctivity must always be encoded by other elements in the sentence. ɦi⁶ in this use serves as an emphatic, strengthening the effect of deontic or imperative force in subjunctive contexts. Furthermore, it is shown that the licensing must obey a locality condition, whereby the expletive ɦi⁶ must be licensed by a c-commanding licenser in its local domain. From the perspective of grammaticalization, I propose that ɦi⁶ is going through an intermediate stage of becoming a purely modal functional marker. A final stage of this “upward” grammaticalization can be found in the expletive use of the third person pronoun keoi in Cantonese, which has become a more grammaticalized marker that has scope over the sentence. It is pointed out that the development of the expletive pronoun suggests that being at the right-periphery is a crucial factor in motivating and facilitating grammaticalization in Chinese. Last, a comparison between the non-referential ɦi⁶ and the Mandarin non-referential third person pronoun ta in the V-ta-ge-NP/AP construction is presented, showing that both cases manifest interactions between VP-internal projections and higher functional categories.