This paper provides cross-linguistic support for a bipartite analysis of ‘only’ (Bayer in Directionality and logical form: on the scope of focusing particles and Wh-in-situ, Springer, Dordrecht 1996; Kayne in Syntax 1:128–191, 1998; Lee in Nat Lang Semant 13:169–200, 2005; Horvath in: Simin et al. (eds) Phrasal and clausal architecture: syntactic derivation and interpretation, John Benjamins, Amsterdam, 2007; Barbiers in Linguistic variation in the minimalist framework, Oxford University Press, Oxford, 2014; Quek and Aron, in: Lamont and Tetzloff (eds) Proceedings of NELS 47, University of Massachusetts, Graduate Linguistic Student Association, Amherst, 2017) by showing that it can be extended to account for all the properties of a focus particle—zhiyou ‘only’ in Mandarin Chinese. It proposes that zhiyou spells out one of the heads within a bipartite structure of ‘only’ and the other covert head that co-occurs with it on the clausal spine determines the semantic scope of ‘only’. The current proposal improves on a previous version of bipartite analysis (Hole in J East Asian Linguist 26:389–409, 2017: A crosslinguistic syntax of scalar and non-scalar focus particle sentences: the view from Vietnamese and Chinese) by discarding the view that zhiyou and the particle cai form a Spec-Head relation, which enables us to cover a wider range of empirical data. Instead, the paper identifies the adverbial zhi ‘only’ as a possible candidate that overtly realizes the Foc head, and supports the bipartite analysis based on the cross-linguistic parallel between Mandarin and Vietnamese, which share a similar inventory of ONLY-related particles.