HPSG Research Articles

The information structure of Danish grammar constructions

This paper addresses the issue of how information structure can be accounted for in a formal grammar of Danish. Three information structure features – topic, focus and background – are discussed, and it is shown how they are instantiated in a number of different grammatical constructions from a corpus of spoken Danish. Prosodic, syntactic and information structure constraints characterising the various constructions are represented as typed feature structures following Head-driven Phrase Structure Grammar (HPSG), and the constructions themselves are ordered in a type hierarchy. The proposed approach modifies and extends earlier HPSG-based accounts by integrating information structure as a dimension of phrasal and clausal grammar constructions.

On the superficiality of Welsh agreement

A notable feature of Welsh is a number of agreement phenomena, all of which only occur with pronouns. Finite verbs agree with a following pronominal subject, prepositions agree with a following pronominal complement, and a particle which introduces non-finite clauses agrees with a following pronominal subject. Similarly, nouns have a preceding clitic agreeing with a following pronominal possessor, non-finite verbs have a preceding clitic agreeing with a following pronominal object, and what looks like the non-finite form of bod “be”, which introduces certain subordinate clauses, has a preceding clitic agreeing with a following pronominal subject. There seems to be a single phenomenon here. Approaches that involve an abstract level face problems and there is no evidence that the phenomenon involves an abstract level. It seems quite plausible to suggest that superficial linear order is crucial, and this idea can be implemented in a straightforward way within linearization-based Head-driven Phrase Structure Grammar (HPSG). The properties of agreement also entail that unexpressed noun phrases of various kinds must be represented in the superficial constituent structure and not just at some abstract level, contrary to the view of some frameworks.

An HPSG Analysis on the Unbounded Dependency Constructions in Chamorro

The Western Austronesian language Chamorro, spoken in the Mariana Islands, has a basic word order VSO and shows an interesting behavior in unbounded dependency constructions (UDCs). When the clause has a gap, the verb of the clause exhibits special agreement morphology: the verb can be nominalized or have a certain infix attached. To explain UDC phenomena in Chamorro, Chung (1982) proposes successive cyclic Wh-movement for wh-questions and Controlled PRO Deletion for relative clauses, respectively. In addition, her analysis also adopts non-local structural descriptions with grammatical features to account for Wh-agreement in UDCs. The purpose of this paper is to show that a constraint-based HPSG analysis can also offer us a straightforward account for Chamorro UDC phenomena in a uniform and principled way.

Linearization-based word-part ellipsis

This paper addresses a phenomenon in which certain word-parts can be omitted. The evidence shows that the full range of data cannot be captured by a sublexical analysis, since the phenomena can be observed both in phrasal and in lexical environments. It is argued that a form of deletion is involved, and that the phenomena—lexical or otherwise—are subject to the same phonological, semantic, and syntactic constraints. In the formalization that is proposed, all of the above constraints are cast in a parallel and declarative fashion, in the framework of Head-Driven Phrase Structure Grammar (Pollard and Sag Head-driven phrase structure grammar, 1994), since the various levels of linguistic description are locally and simultaneously available. Building on recent accounts of ellipsis, this paper proposes a unified and general account of word-part ellipsis and phrasal ellipsis.

Polyadic Dynamic Logics for HPSG Parsing

Head-driven phrase structure grammar (HPSG) is one of the most prominent theories employed in deep parsing of natural language. Many linguistic theories are arguably best formalized in extensions of modal or dynamic logic (Keller, Feature logics, infinitary descriptions and grammar, 1993; Kracht, Linguistics Philos 18:401---458, 1995; Moss and Tiede, In: Blackburn, van Benthem, and Wolther (eds.) Handbook of modal logic, 2006), and HPSG seems to be no exception. Adequate extensions of dynamic logic have not been studied in detail, however; the most important aspect is the reference to sets of substructures. In this paper, an adequate extension is identified, and some important results are established: Satisfiability is highly undecidable, and model checking is shown to be in EXPTIME and PSPACE-hard. A fragment with polynomial time model checking procedures is identified; it is shown to cover considerable fragments of HPSG.

An HPSG approach to Arabic nominal sentences

AbstractThis paper introduces a grammar for Arabic nominal sentences written in the formalism of Head‐Driven Phrase Structure Grammar (HPSG). This grammar covers simple Arabic nominal sentences, though the same approach can be extended to cover other types of Arabic nominal sentences. The formalization has been implemented using the Linguistic Knowledge Building (LKB) system.

A (phrasal) affix analysis of the Persian Ezafe

This paper discusses the status of the Ezafe particle -(y)ein Persian and provides an affixal analysis of the Ezafe, formalized within Head-driven Phrase Structure Grammar (HPSG). The Ezafe, a feature of certain Western Iranian languages, is realized as an enclitic and links the head noun to its modifiers and to the possessor NP. The latter follow the head and are linked to one another by the Ezafe. On the basis of crucial empirical facts that have never been discussed in previous studies, I argue that the Ezafe is best regarded as an affix attaching to nominal heads (nouns, adjectives and some prepositions), as well as to nominal intermediate projections, and marking them as expecting a modifier or a direct nominal complement. Viewed as such, the Ezafe construction is an instance of the head-marked pattern of morphological marking of grammatical relations. This analysis differs from all previous accounts of the Ezafe (i.e. as case-marker, syntactic or phonological linker) and entails that the Ezafe, which originated in the Old Iranian relative particle -hya, has undergone a process of reanalysis-grammaticalization, to end up as a part of nominal morphology.

A description of Chinese NPs using Head-Driven Phrase Structure Grammar

This paper aims at making a general description of Chinese NPs using Head-Driven Phrase Structure Grammar. The paper introduces the basic and complex structures of Chinese NPs and then shed light on the noun-classifier matching problem when implemented in HPSG. To solve this problem, the paper tries to establish a basic grammar of Chinese NPs in the framework of HPSG, which is implemented in the LKB system. The implementation shows, although the matching problem between noun and classifier can be described in HPSG, especially by the MRS, it is still difficult to efficiently represent the semantic constrains in the LKB system.

From “Hand-written” to Computationally Implemented HPSG Theories

The process of turning a “hand-written” head-driven phrase structure grammar (HPSG) theory into a working computational grammar requires complex considerations. Two leading platforms are available for implementing HPSG grammars: The LKB and TRALE. These platforms are based on different approaches, distinct in their underlying logics and implementation details. This paper adopts the perspective of a computational linguist whose goal is to implement an HPSG theory. It focuses on ten different dimensions, relevant to HPSG grammar implementation, and examines, compares, and evaluates the different means which the two approaches provide for implementing them. The paper concludes that the approaches occupy opposite positions on two axes: expressiveness and computational accessibility. The choice between them depends largely on the “style” of the “hand-written” grammar and the grammar writer’s preferences regarding those properties.

Morph Moulder: Teaching Software for HPSG and Description Logics

The graphical software Morph Moulder (MoMo) presented here was originally created for teaching the logical foundations of Head-Driven Phrase Structure Grammar (HPSG) in an e-Learning environment. It has then been extended to a treatment of description logics (DL), which are at present the standard formalism for building ontologies. With MoMo, students can construct interpretations of sets of formulae and check whether their interpretations model these formulae (called theory in HPSG and axioms in DL). MoMo also supports reasoning such as the construction of well-formed interpretations in the feature logic of HPSG and the automatic extraction of subsumption hierarchies in DL. It has been used successfully in several courses on HPSG linguistics, on computational grammar implementation and on the logical foundations of constraint-based grammar frameworks.

Special issue on English dialect syntax

This special volume is concerned with the syntax of nonstandard varieties of (mainly British) English, and how such syntactic variation is accounted for within a range of theoretical models. There has been a growing interest in the modelling of dialect syntax (a) in a number of languages and (b) in a number of syntactic theories (see, for instance, the research on syntactic microvariation in some Germanic languages in Barbiers, Cornips & van der Kelij, 2002, or the construction-based approach to variation in Leino & Östman, 2005). We have brought together five articles written in different theoretical frameworks (Principles and Parameters, Stochastic Optimality Theory, Head-driven Phrase Structure Grammar, Word Grammar, and Construction Grammar), together with an introduction written by the editors, who themselves adopt very different theoretical frameworks.

Argumento, sintagma e saturador no escopo da HPSG

This work presents the formalization of argument as interfacial feature structure between phonology, syntax and semantics. It also shows that argument, phrase and saturator are distinct entities, although they may be related to each other. Such a distinction is based on the observation that an argument, differently from a phrase and a saturator, is an entity that is inherent to the meaning of the nucleus it is part of. The theoretical framework used is the Head-driven Phrase Structure Grammar (HPSG), a model of grammar which is strongly lexicalist, surface oriented and based on the notion of Saussurean sign. Key words: argument, phrase, saturator, HPSG.

The Emergence of Second Language Syntax: A Case Study of the Acquisition of Relative Clauses

One of the great puzzles of language acquisition has been described as poverty of the stimulus: how are complex aspects of language acquired when they appear to be rare or even non-occurring in the input that a learner receives and comprehends? This article presents an emergentist solution to one aspect of this puzzle (involving relative clauses) by examining the longitudinal development of meaningful discourse produced by Ana, a 12-year-old Spanish learner of English. Relative clause constructions are considered in terms of learnable, non-abstract linguistic analyses (lexicalist signs and constructions; dependencies), informed by emergentist syntax (O'Grady 2005), analyses within Head-driven Phrase Structure Grammar (Sag 1997), and a comprehensive corpus grammar (Biber et al. 1999). The data show that complex aspects of language gradually emerged from item-based and compositional learning processes that interacted with the learner's environment, including input frequency and the functional purposes for which language is used. Item-based, sign-based, and compositional analyses of constructions are valuable for syllabus design (for synthetic syllabi) and for the evaluation of language proficiency (i.e. testing and measurement).

A linear approach to negative prominence

Languages often require negation to be realized in a prominent position. A well known example is Italian, which seems to require a pre-verbal realization of negation. Some other languages require negation to be in a prominent position but do not require it to be pre-verbal. An example is Swedish. Working within Lexical Functional Grammar (LFG), Sells (2000) proposes that Swedish requires a negative element which is not inside VP and that Italian has the same constraint. Similar facts are found in the VSO language Welsh. However, Sells’s approach cannot be applied to Welsh. Borsley and Jones (2005) develop a selectional approach to Welsh, in which certain verbs require a negative complement. This works well for Welsh but cannot be applied to Swedish or Italian. A similar approach to all three languages is possible within the linearization-based version of Head-driven Phrase Structure Grammar (HPSG) developed by Kathol (2000). It seems, then, that a linear approach is preferable to both a structural and a selectional approach.

An HPSG account of closest conjunct agreement in NP coordination in Portuguese

This paper discusses the NP-internal agreement strategies observed in an empirical (corpus based) study of Portuguese, and proposes an analysis which is formalized in the framework of Head-Driven Phrase Structure Grammar (HPSG). The empirical study suggests that what were previously thought to be rare or non-existent strategies occur with surprising frequency. Capturing these strategies poses problems for many standard approaches to agreement. The formalization shows how they can be captured with a relatively conservative extension of the existing HPSG theory of agreement.

Records and Record Types in Semantic Theory

This paper explores possibilities for formulating linguistic semantics in terms of records and record types of the kind used in recent developments of Martin-Lof type theory. We will suggest that this gives us tools to develop a single theory which includes aspects of Montague semantics, Discourse Representation Theory, situation semantics and Head-Driven Phrase Structure Grammar. We will also argue that formulating these theories in terms of record types may provide us not only with a unified approach but also with certain improvements over the individual theories.

Broad-Coverage Parsing with Neural Networks

Subsymbolic systems have been successfully used to model several aspects of human language processing. Such parsers are appealing because they allow revising the interpretation as words are incrementally processed. Yet, it has been very hard to scale them up to realistic language due to training time, limited memory, and the difficulty of representing linguistic structure. In this study, we show that it is possible to keep track of long-distance dependencies and to parse into deeper structures than before based on two techniques: a localist encoding of the input sequence and a dynamic unrolling of the network according to the parse tree. With these techniques, the system can nonmonotonically parse a corpus of realistic sentences into parse trees labelled with grammatical tags from a broad-coverage Head-driven Phrase Structure Grammar of English.

On the nature of Welsh VSO clauses

Welsh is a VSO language, in which the verb precedes the subject in finite clauses. It is widely assumed that such clauses have a basic SVO structure. This idea is not limited to Principles and Parameters/Minimalist work, but is also found in Lexical-Functional Grammar and it could also be incorporated into Head-driven Phrase Structure Grammar. Other things being equal, an analysis which involves an SVO structure is more complex than one that does not. Thus, the burden of proof is on advocates of an SVO structure. Arguments for such an analysis have been advanced or might be advanced on the basis VP-like constituents, anaphora, coordination and ellipsis. A close inspection of the arguments suggests that none is very compelling. Moreover, some SVO analyses face problems with agreement, negation or mutation. It seems, then, that an analysis which does not involve an SVO structure is preferable.

Raising doubts about Russian impersonals

The Russian data presented in Perlmutter and Moore (2002) seem to call into question the standard analysis of raising within Head-driven Phrase Structure Grammar (HPSG): In Russian, the case marking of the raising target and raising pivot does not seem to be shared. In this paper, we show that the phenomena described by Perlmutter and Moore can receive another analysis, fully compatible with HPSG's theory of raising. We argue in addition that our account leads to a slightly simpler model of the Russian data than Perlmutter and Moore's. Crucially, our analysis is only available if we avail ourselves of a rich network of language-specific constructional schemata, a stance recently advocated within HPSG, following the lead of Construction Grammar.

Connectionism, HPSG signs and SLA representations: specifying principles of mapping between form and function

A current limitation of the connectionist approach to second language acquisition (SLA) research is that it does not, to my knowledge, include complex linguistic representations. This article proposes a partial solution to this limitation by motivating and illustrating specific analyses that utilize the sign-based representations developed within Head-driven Phrase Structure Grammar (HPSG). To motivate the proposed representations, the article applies them to an analysis of four types of mappings between form and function: one-to-one, primed redundancy, nonprimed redundancy and polyfunctional. The paper summarizes representative SLA data that indicate how these mappings may appear in second language (L2) production. Key properties of HPSG analyses are discussed, indicating how they are consistent with connectionist assumptions. Sign-based representations of the four types of mappings are then provided, including several modifications to HPSG formalisms. The article concludes with a discussion of future directions.