This paper investigates the syntactic status of nominal modifiers in Isbukun Bunun, an Austronesian language spoken in Taiwan. In Isbukun Bunun, nominal modifiers such as possessors, adjectives, demonstratives, and relative clauses precede the head noun they modify, and they may or must be linked to the head noun by an associative marker tu. Based on the observed NP-ellipsis facts and the formal licensing condition, I argue that the associative marker tu is a complementizer, and the structure it introduces should be accommodated under the adjunction analysis, whereas various existing alternative complementation approaches that view tu as a head selecting the modified phrase as its complement fail to capture the noted properties regarding ellipsis. 1. INTRODUCTION. (1) In many languages, complex noun phrases contain an apparently meaningless, and sometimes optional, element whose function is to provide a link between modifiers and modifiees. The existence of such a linking element or associative marker is attested in several Formosan Austronesian languages (He et al. 1986; Huang 1997,2000; Chang 2000; Wu 2000; Zeitoun 2000; Tang 2007), and in a considerable number of other languages (cf den Dikken and Singhapreecha 2004), as exemplified in (1): (1) a. PAIWAN va'uan a kun new A skirt 'a new skirt' b. AMIS ma-su'su'-ay a tamdaw AV-fat-FAC A person 'a fat person' c. THAI khon thii ken person THII smart 'a smart person' d. MANDARIN CHINESE huangse de chenshan yellow DE shirt 'a yellow shirt' In the principles-and-parameters framework, grammatical constructions arise from the universal principles that work in tandem with parameters with values set for particular languages; therefore, it is very often shown that some intuitively equivalent constructions in two languages involve very different syntactic representations, since there are no a priori universal rules specific to a given construction. This paper examines complex noun phrases in Isbukun Bunun (often referred to as just Isbukun in this paper), and explores the nature of the associative element tu as well as the modification structure in this language. I will examine the existing approaches to such linking elements and investigate whether phrases like (2) should be analyzed as a relative construction or a pure complex nominal construction--or even some other construction. In particular, a careful examination of Isbukun nominal structure shows that Kayne's (1994) antisymmetry theory, which hypothesizes that phrase structure is universally head-initial, does not account for the syntactic patterns of complex noun phrases in Isbukun. (2) ISBUKUN BUNUN madiav *(tu) ulus AV.yellow TU clothes 'yellow clothes' This paper is structured as follows. Section 2 first provides some basics of the morphosyntax of Isbukun, and subsequently introduces the Isbukun tu-construction that is the focus of this study. Section 3 discusses possible accounts for the associative marker as pointed out in the literature, and further argues that tu is a complementizer that introduces an adjoined pure sentential modifier phrase to the modifiee, mainly based on the evidence from ellipsis. Section 4 concludes the paper. 2. THE EMPIRICAL BASE. Bunun is a Formosan Austronesian language spoken in Taiwan. The current study is based on the Isbukun dialect spoken in Taitung County. (2) Isbukun Bunun is a predicate-initial, or more specifically VSO, language (He et al. 1986; Li 1997; Huang 1997; Jeng 1999; Zeitoun 2000; Wu 2013). Just like many other Formosan and Western Austronesian languages, Isbukun Bunun permits a range of arguments to serve as the syntactically most prominent NP of the clause, marked by the a nominative case marker. Such an a-marked phrase has been known by a number of names in the Austronesian literature, including "subject," "topic," and "pivot"; here 1 will refer to it as the subject for ease of presentation, though this term should be regarded with caution. …