The locality conditions of head movement have long been a debate in movement theory. It is often suggested that head movement is exceptionally restricted compared to phrasal movement, being blocked by intervening heads (i.e., the Head Movement Constraint). I argue against the presence of head-movement-specific locality conditions, and propose instead that both head movement and phrasal movement are subject to the same set of locality constraints, i.e., both of them are disrupted by featural interveners, instead of structural interveners. The empirical foundations come from an array of verb doubling constructions in Cantonese, where a copy of a verb appears in the (left or right) periphery. I observe that these constructions not only obey island constraints and allow for cross-clausal dependencies, but also exhibit the so-called Focus Intervention Effects, where intervening focused elements disrupt the dependencies between verbs. However, heads do not have a similar blocking effect in these constructions, posing empirical challenges to the Head Movement Constraint. I suggest assimilating these movement properties to phrasal movement such as wh-movement and focus movement. Relatedly, I examine head dependencies across coordination and subordination, such as ATB-movement and parasitic gaps.

Head movement lacks semantic effects in an array of cases, and appears to be substantially distinguished from phrasal movement. I present empirical challenges to this distinction by observing that quantificational heads such as aspectual verbs and modal verbs in Cantonese exhibit a high vs. low positional alternation under certain circumstances. I propose that they can undergo scope-shifting head movement, which redefines the quantificational or focus scope of the quantificational heads. The suggested movement shares a crucial property with Quantifier Raising: both of them are constrained by an economy condition on scope interpretation (i.e., Scope Economy).

Doubling effects of predicate clefts are attested in language after language. While it appears that verb movement is exceptional in allowing multiple realizations as compared to its phrasal counterpart, data in Cantonese suggest that this is at best a tendency, rather than a generalization. I observe that (i) not all cases of predicate clefts require verb doubling and that (ii) not all cases of phrasal movement disallow doubling. I propose to derive the different doubling patterns of head movement and phrasal movement through the different launching positions of these elements, instead of some particular properties of head movement. The proposal is implemented under a cyclic linearization/spell-out approach to syntactic structure, revealing the tension between minimizing movement copies and maximizing the easiness of the linearization process. Most importantly, the very mechanism of linearizing syntactic structure does not distinguish head movement from phrasal movement. In ongoing work, I revisit Parallel Chains as a source of repetition (with Ka-Fai Yip), and compare verb doubling with VP dislocation in Mandarin (with Zijie Yang).

Whether or not raising of subjects/objects out of a CP (i.e., hyperraising constructions) is allowed divides languages into two classes. In my joint work with Ka-Fai Yip, we observe that the legitimacy of subject raising in both Cantonese and Vietnamese independently reveals a correlation with the requirement of indirect evidence of the embedding predicates. For example, a subset of attitude verbs such as ‘guess’ and ‘believe’ allow hyperraising constructions in these languages, but not other verbs such as ‘think’ and ‘know’. This language-internal variation calls for a more fine-grained analysis on the availability of hyperraising constructions. We propose that while CP is by default a phase, it may be selectively “opened up” by an Agree relation with the attitude verbs that encode indirect evidence. The proposal implies that the phasehood of CP interacts with syntactic dependencies and that locality conditions exhibit certain degrees of flexibility. (Joint work with Ka-Fai Yip)

While vP is often characterized as the first clause-internal phase, independent evidence shows that there is certain flexibility in the minimal size of this first phase. In my joint work with Victor Junnan Pan, we establish further support for this idea based on the licensing conditions of VP movement and ellipsis in Mandarin and Cantonese. The core observations build on the inability of certain aspectual elements, such as progressive markers and aspectual verbs, to license VP fronting, VP postposing and VP ellipsis. These elements contrast with perfective markers, for example. To derive the distinction between different aspectual elements in this regard, we develop an account that assigns a privileged status to phases in licensing VP movement and ellipsis, and motivate a contextual approach to phasehood. Specifically, the aspectual phrase that hosts imperfective elements, when projected, replaces vP as a phase, rendering the complement vP a non-phase (hence unmovable and unelidable). In other words, the size of the first phase is determined contextually. (Joint work with Victor Junnan Pan)

How movement chains are pronounced is a central issue of any theory of linearization (i.e., the mechanism that maps structures onto linear strings). As an attempt to reveal the underlying properties of this mechanism, this project zooms in on two non-canonical realizations of movement chains, namely, (i) verb doubling (where gaps are fully pronounced), and (ii) discontinuous predicates (where gaps are partially pronounced). Drawing on evidence from a range of verb movement in Cantonese, I propose that the Economy condition serving to minimize copies (i.e., members of a movement chain) compromises when confronted with (i) Syntactic Cyclicity and (ii) the Faithfulness condition on copy integrity. Non-canonical or Economy-violating patterns arise as a result of avoiding violations of other hardwired principles.

Copy Deletion is held responsible for erasing extra copies created in movement chains, and partial (copy) deletion is proposed to derive discontinuous phrasal constituents such as split topics in German and left-branch extraction in Serbo-Croatian. In principle, nothing a priori rules out the possibility of partial deletion applying to head chains. In my joint work with Ka-Fai Yip and Sheila Shu-Laam Chan, we fill the theoretical gap through an in-depth study of discontinuous predicates in Cantonese, where a (disyllabic) predicate is “split” into two parts by elements such as verbal suffixes and wh-expressions. We propose that discontinuous predicates in Cantonese result from a combination of a syllable deletion rule induced by affixes in the language and a subsequent application of partial deletion. The proposal implies that partial deletion is not restricted to phrases but applies also to heads. It also reveals that partial deletion applies instead of (full) copy deletion so as to avoid a violation of a faithfulness condition when determining copy pronunciation. Further work extends the analysis to parametric variation across Sinitic languages and to verbal suffixation in Chinese, and examines the processing of discontinuous predicates (with Carmen Tang). (Joint work with Ka-Fai Yip and Sheila Shu-Laam Chan)

Right dislocation poses various puzzles for the theory of linearization. Based on evidence from Cantonese right dislocation, I propose to derive the surface word order in right dislocation through multiple leftward movements. The first movement step involves A’-movement (defocalization) that may target both heads and phrases, followed by a subsequent movement of TP to the specifier position of the projection headed by sentence-final particles. The proposal accounts for data left unexplained in previous accounts of right dislocation in Cantonese, and provides further support for head movement to specifier positions. I also look at the information-structural status of right-dislocated elements in Cantonese, Japanese and Mongolian (based on my fieldwork on Alasha Mongolian), and at the licensing of Focus Projection in East Asian languages.

With Jianing Yang, I examine resumptive pronouns in Mandarin that do not agree in number with their antecedents, and what such mismatches reveal about how resumptive pronouns are realized. (Joint work with Jianing Yang)

I compare predicate ellipsis and verbal anaphora across East Asian languages: the division of labor between clausal and predicate ellipsis in Japanese, verbal anaphora without an overt do in Mandarin, and the Head Licensing Condition on VP ellipsis in the light of you-NP-VP in Mandarin. In joint work with Yuyang Liu, I also investigate why pseudogapping occurs in some languages but not in others, including its absence in Cantonese.

In joint work with Xue Bai, I examine sluicing-like constructions and reduced embedded clauses in Mandarin, Mongolian and Uyghur, including the availability of “sloppy” identity readings and the symmetries and asymmetries between surface and deep anaphora in sluicing and stripping.

Building on earlier work decomposing wh-expressions in Cantonese, Hok-Yuen Wong and I study phrasal and clausal wh-doublets in Cantonese. We propose a conjunction approach to them, examine how they encode evidentiality and plurality, and consider their typological implications. (Joint work with Hok-Yuen Wong)

Wenze Wu and I examine Chinese why-expressions that do not contribute a reason meaning, focusing on their occurrence in embedded contexts and under grumble predicates. (Joint work with Wenze Wu)

I study the distribution, interpretation, and syntax of the free choice item sidaan in Cantonese (in part with Sze Ching Tsang) and the free choice marker suibian in Mandarin.

In languages without morphological marking of tense, it is a debate whether they are tensed languages with covert morphology or genuinely tenseless languages. In my joint work with Maria Luisa Zubizarreta and Roumyana Pancheva, we pursue an account that invokes no use of tense to derive temporal reference in Cantonese. We propose that temporal reference is expressed via evaluation time shift, a mechanism adopted to explain the narrative present in English. We argue that the notion of (neo-Reichenbachian) tense is unnecessary in Cantonese, and falls short of capturing temporal reference in this language. The proposal implies that tense is not a universal semantic notion. (Joint work with Roumyana Pancheva and Maria Luisa Zubizarreta)

The relative strength of necessity modals (e.g., must vs. should) receives a lot of attention in the literature. A question arises as to whether a similar distinction is found in possibility modals. I suggest that the expression you-liyou ‘have-reason’ in Mandarin exemplifies such a possibility. The expression is logically stronger than the possibility modal keyi ‘may/can’ and it stands in a dual relation with yinggai ‘should’. The proposal exhausts the four possibilities entailed by two parameters in modal discussions: force and strength.

A recent line of research focuses on the modal meaning in the nominal domain. In a number of languages, certain grammatical markings on indefinites convey an ignorance component typically oriented to the speaker, opening up the discussion of epistemic modality in the nominal domain. I conduct a case study of epistemic indefinites in Cantonese, which arguably take the form of m-zi ‘not-know’ + wh-expressions. I argue that the associated ignorance component is a presupposition (instead of a conversational implicature) encoded by m-zi, which is grammaticalized as a choice function. The proposal enriches the landscape of epistemic indefinites and sheds light on the interpretation of wh-expressions in Cantonese.

I examine the syntax and semantics of classifiers in Cantonese, and how their interpretation relates to their structural position in the nominal domain.

Hong Kong Cantonese code-mixing speech features an emerging construction with the English word which. I revisit what is borrowed and what is not in this construction, and argue that it is a clausal parenthetical in disguise, involving predication rather than a canonical relative clause.

With Tyra Wai-Nga Cheung, I examine the use of single-word English prepositions in Cantonese–English code-switching. (Joint work with Tyra Wai-Nga Cheung)