Grammatical Framework Research Articles

Lexico-grammatical Framework of a Politeness Category in Russian and Korean

This paper presents research on subject pronouns such as “Ty” (You) and “Vy” (polite form of You) from the perspective of expressing politeness. Politeness is explored as a communicative category, which has various connotations in different cultures. Second person singular subject pronouns have different roles when comparison is drawn between the two languages. For instance, second person subject pronouns are indicators of two forms of politeness in Russian such as informal and formal when addressing somebody using “Ty” and “Vy” respectively. Second person subject pronouns in the Korean language do not indicate forms or degrees of politeness, but they are the means of expressing politeness. It is presented in the paper that second person object pronouns in Russian are related to “terms of address” as an indicator of social etiquette and the attitude of a speaker towards an interlocutor (close versus distant) as well as their social roles in the society (superior vs inferior, elderly vs young). Meanwhile in the Korean language forms of politeness are divided into official and unofficial, which implies that politeness in Korean is social in nature and depends on the communicative situation (formal or informal). In contrast with Korean politeness, pragmalinguistic meaning of politeness forms in Russian have the connotation of proximity, closeness (or familiarity) and distancing (or showing respect) when the subject pronouns “Ty” and “Vy” are used respectively. Yet, Korean degrees of politeness have major differences to show various levels of respect or a lack of it. Comparative analysis of second person singular pronouns in both languages showed that subject pronouns have differences from the perspective of structure, semantics and function. As for structural differences, pronouns in Korean compared to Russian pronouns, are included into the category of content words. The functional difference is that pronouns in Russian indicate a degree of politeness and are used in different forms of politeness (“Ty” and “Vy”). Semantic and linguistic aspect of a politeness category relies on the the lexical and grammatical framework, so in Korean it is a grammatical system of politeness, whereas in Russian it is a system of subject pronouns such as “Ty” and “Vy”. Lexical and grammatical features of the two languages compared in this work show that politeness in the Russian language is interpersonal in nature, it indicates the formal and informal nature of communication, which is expressed through strategies used by communicators to become either close or distant. In the Korean language politeness is social in nature and depends on the level of formality of a particular communicative situation.

Abstract Syntax as Interlingua: Scaling Up the Grammatical Framework from Controlled Languages to Robust Pipelines

Abstract syntax is an interlingual representation used in compilers. Grammatical Framework (GF) applies the abstract syntax idea to natural languages. The development of GF started in 1998, first as a tool for controlled language implementations, where it has gained an established position in both academic and commercial projects. GF provides grammar resources for over 40 languages, enabling accurate generation and translation, as well as grammar engineering tools and components for mobile and Web applications. On the research side, the focus in the last ten years has been on scaling up GF to wide-coverage language processing. The concept of abstract syntax offers a unified view on many other approaches: Universal Dependencies, WordNets, FrameNets, Construction Grammars, and Abstract Meaning Representations. This makes it possible for GF to utilize data from the other approaches and to build robust pipelines. In return, GF can contribute to data-driven approaches by methods to transfer resources from one language to others, to augment data by rule-based generation, to check the consistency of hand-annotated corpora, and to pipe analyses into high-precision semantic back ends. This article gives an overview of the use of abstract syntax as interlingua through both established and emerging NLP applications involving GF.

The Syntax of Jazz Harmony: Diatonic Tonality, Phrase Structure, and Form

The regularities underlying the structure building of chord sequences, harmonic phrases, and combinations of phrases constitute a central research problem in music theory. This article proposes a formalization of Jazz harmony with a generative framework based on formal grammars, in which syntactic structure tightly corresponds with the functional interpretation of the sequence. It assumes that chords establish nested hierarchical dependencies that are characterized by two core types: preparation and prolongation. The approach expresses diatonic harmony, embedded modulation, borrowing, and substitution within a single grammatical framework. It is argued in the second part that the proposed framework models not only core phrase structure, but also relations between phrases and the syntactic structures underlying the main forms of Jazz standards. As a special case, the Blues form relies heavily on the plagal derivation from the tonic and is analyzed in comparison with other analytical approaches to the Blues. The proposed theory is specified to a sufficient level of detail that it lends itself to computational implementation and empirical exploration, and this way it makes a step towards music theory building that embraces the close links between formal, mathematical, and computational methods.

Difficulties assessing knowledge of grammatical terminology: implications for teacher education and teaching

ABSTRACT This paper starts by reporting on the design and trialling of an informal, low-stakes test designed to assess the knowledge of grammar terms of pre-service primary school teachers following the UK’s National Curriculum, the results of which were used to inform the design of a series of optional grammar classes. The test proved surprisingly difficult to design, and the final version contains many flaws, some predictable and some less so. In this paper we describe the design process and illustrate the difficulties we encountered, using evidence from our contemporaneous discussions and notes, as well as qualitative feedback and selected results from student teachers’ test scores. We speculate on the extent to which the problems of our test reflect underlying issues with our understanding of the nature of declarative grammatical knowledge; these issues are likely to be relevant in all contexts where formal grammar is taught. We also draw out specific implications for the grammatical framework used in the English National Curriculum, and the associated tests of grammar, punctuation and spelling currently in use.

Extended grammar: Malay and the Arabic tradition

Throughout history, a number of languages have achieved the status of learned language, i.e., a language included in the curriculum of an educational system without yielding any communicational benefits. In large parts of the Islamic world, Arabic was (and still is) such a learned language. Acquisition of the learned language took place through the memorization of texts, with instruction and/or translation in vernacular languages. The vernacular languages themselves were not deemed to be in need of grammatical description, which explains why grammars for them were late to be developed. The present paper focuses on Malay, the lingua franca of choice in Southeast Asia for both Muslim missionaries and British and Dutch colonial administrators, while serving as the auxiliary language in the Islamic curriculum. The first grammars of Malay were published by the British and Dutch. Malay grammars written by native speakers did not make their appearance until the nineteenth century. Their main representative is Raja Ali Haji (d. probably 1873). In his Bustān al-kātibīn, he used the grammatical framework of Arabic grammar for a grammatical sketch of Malay, using in part the Malay terminology that had been developed in traditional education for the study of Arabic grammar and Qurˀānic exegesis.

Computational Psycholinguistics

Computational Psycholinguistics

GF + MMT = GLF – From Language to Semantics through LF

These days, vast amounts of knowledge are available online, most of it in written form. Search engines help us access this knowledge, but aggregating, relating and reasoning with it is still a predominantly human effort. One of the key challenges for automated reasoning based on natural-language texts is the need to extract meaning (semantics) from texts. Natural language understanding (NLU) systems describe the conversion from a set of natural language utterances to terms in a particular logic. Tools for the co-development of grammar and target logic are currently largely missing. We will describe the Grammatical Logical Framework (GLF), a combination of two existing frameworks, in which large parts of a symbolic, rule-based NLU system can be developed and implemented: the Grammatical Framework (GF) and MMT. GF is a tool for syntactic analysis, generation, and translation with complex natural language grammars and MMT can be used to specify logical systems and to represent knowledge in them. Combining these tools is possible, because they are based on compatible logical frameworks: Martin-L\"of type theory and LF. The flexibility of logical frameworks is needed, as NLU research has not settled on a particular target logic for meaning representation. Instead, new logics are developed all the time to handle various language phenomena. GLF allows users to develop the logic and the language parsing components in parallel, and to connect them for experimentation with the entire pipeline.

Natural Language Generation for Non-Expert Users

Motivated by the difficulty in presenting computational results, especially when the results are a collection of atoms in a logical language, to users, who are not proficient in computer programming and/or the logical representation of the results, we propose a system for automatic generation of natural language descriptions for applications targeting mainstream users. Differently from many earlier systems with the same aim, the proposed system does not employ templates for the generation task. It assumes that there exist some natural language sentences in the application domain and uses this repository for the natural language description. It does not require, however, a large corpus as it is often required in machine learning approaches. The systems consist of two main components. The first one aims at analyzing the sentences and constructs a Grammatical Framework (GF) for given sentences and is implemented using the Stanford parser and an answer set program. The second component is for sentence construction and relies on GF Library. The paper includes two use cases to demostrate the capability of the system. As the sentence construction is done via GF, the paper includes a use case evaluation showing that the proposed system could also be utilized in addressing a challenge to create an abstract Wikipedia, which is recently discussed in the BlueSky session of the 2018 International Semantic Web Conference.

Synthesis of a DNF formula from a sample of strings using Ehrenfeucht–Fraïssé games

In order to define a DNF version of first-order sentences over strings in which atomic sentences represent substring properties of strings, we use results of the Ehrenfeucht–Fraïssé game over strings. Then, given a sample of strings and the number of disjunctive clauses, we investigate the problem of finding a DNF formula that is consistent with the sample. We show that this problem is NP-complete, and we solve it by a translation into Boolean satisfiability. We also present an extension of this problem that is robust concerning noisy samples. We solve the generalized version by a codification into the maximum satisfiability problem. As first-order logic over strings defines exactly the class of locally threshold testable (LTT) languages, our results can be useful in the grammatical inference framework when the goal is to find a model of a LTT language from a sample of strings.

How flexible are idioms? A corpus-based study

AbstractIdioms are a compelling subject of study for linguists, lexicographers and psycholinguists due to their seemingly idiosyncratic status as lexical units that pose challenges for integration into accepted grammatical frameworks. The literature reveals much disagreement on the semantic compositionality, syntactic flexibility and lexical variation of both specific idioms and idioms as a class. We analyze some of the sources for the disparate analyses, which are most often based on judgments of constructed rather than attested examples. Relying solely on corpus data from English and German that shows a wide range of syntactic and lexical variation independent of semantic compositionality, we argue that speakers’ use of idioms is in fact compatible with the rules governing freely composed language.This article is based on a talk given at the BSGL 2015 meeting on idioms in Brussels (Fellbaum 2015b).

Towards Kikamba Computational Grammar

The under-resourced Kikamba language has few language technology tools since the more efficient and popular data driven approaches for developing them suffer from data sparseness due to lack of digitized corpora. To address this challenge, we have developed a computational grammar for the Kikamba language within the multilingual Grammatical Framework (GF) toolkit. GF uses the Interlingua rule-based translation approach. To develop the grammar, we used the morphology driven strategy. Therefore, we first developed regular expressions for morphology inflection and thereafter developed the syntax rules. Evaluation of the grammar was done using one hundred sentences in both English and Kikamba languages. The results were an encouraging four n-gram BLEU score of 83.05% and the Position independent error rate (PER) of 10.96%. Finally, we have made a contribution to the language technology resources for Kikamba including multilingual machine translation, a morphology analyzer, a computational grammar which provides a platform for development of multilingual applications and the ability to generate a variety of bilingual corpora for Kikamba for all languages currently defined in GF, making it easier to experiment with data driven approaches.

Generative Grammar, Neural Networks, and the Implementational Mapping Problem: Response to Pater

The target article (Pater 2019) proposes to use neural networks to model learning within existing grammatical frameworks. This is easier said than done. There is a fundamental gap to be bridged that does not receive attention in the article: how can we use neural networks to examine whether it is possible to learn some linguistic representation (a tree, for example) when, after learning is finished, we cannot even tell if this is the type of representation that has been learned (all we see is a sequence of numbers)? Drawing a correspondence between an abstract linguistic representational system and an opaque parameter vector that can (or perhaps cannot) be seen as an instance of such a representation is an implementational mapping problem. Rather than relying on existing frameworks that propose partial solutions to this problem, such as harmonic grammar, I suggest that fusional research of the kind proposed needs to directly address how to ‘find’ linguistic representations in neural network representations.

Generative grammar, neural networks, and the implementational mapping problem: Response to Pater

The target article (Pater 2019) proposes to use neural networks to model learning within existing grammatical frameworks. This is easier said than done. There is a fundamental gap to be bridged that does not receive attention in the article: how can we use neural networks to examine whether it is possible to learn some linguistic representation (a tree, for example) when, after learning is finished, we cannot even tell if this is the type of representation that has been learned (all we see is a sequence of numbers)? Drawing a correspondence between an abstract linguistic representational system and an opaque parameter vector that can (or perhaps cannot) be seen as an instance of such a representation is an implementational mapping problem. Rather than relying on existing frameworks that propose partial solutions to this problem, such as harmonic grammar, I suggest that fusional research of the kind proposed needs to directly address how to ‘find’ linguistic representations in neural network representations.

Integrating LFG’s binding theory with PCDRT

We provide a formal model for the interaction of syntax and pragmatics in the interpretation of anaphoric binding constraints on personal and reflexive pronouns. We assume a dynamic semantics, where e-type expressions introduce discourse referents, and contexts are assignments of individuals to discourse referents. We adopt the Partial Compositional Discourse Representation Theory (PCDRT) of Haug(2014b),which models anaphoric resolution in terms of a pragmatically-established relation between discourse referents. We integrate PCDRT into the constraint-based grammatical framework of Lexical-Functional Grammar (LFG), and show how it is possible to state syntactic constraints on the pragmatic resolution of singular and plural anaphora within this framework.

Deriving bounded tone with layered feet in Harmonic Serialism: The case of Saghala

This paper proposes an approach to bounded tone shift and spread as found in Bantu languages. Its core intuition is that the bounding domain is delimited by foot structure. The approach uses layered foot representations to capture ternary phenomena, following Martinez-Paricio & Kager (2015). A set of licensing and structural constraints regulate tone-foot interactions. Harmonic Serialism is adopted as the grammatical framework, to allow for an account of opaque patterns (Prince & Smolensky 1993/2004; McCarthy 2010a).The present approach improves on previous accounts in two ways. Firstly, the size of the tonal bounding domain follows from independently motivated foot representations, rather than being stipulated in the constraint set. Secondly, the approach obviates the need for markedness constraints that refer to underlying structure, because all relevant lexical information is reflected in foot structures.The approach is demonstrated on Saghala (Patin 2009). Saghala shows both shift and spread in a trisyllabic domain. There are six tone patterns, dependent on the contact or near-contact of tones, and the position of word boundaries. An analysis is presented that accounts for all patterns. The success of the analysis shows that the foot-based approach is equipped to deal with a variety of bounded tone phenomena.

Question answering over biomedical linked data with Grammatical Framework

The blending of linked data with ontologies leverages the access to data. GFMed introduces grammars for a controlled natural language targeted towards biomedical linked data and the corresponding controlled SPARQL language. The grammars are described in Grammatical Framework and introduce linguistic and SPARQL phrases mostly about drugs, diseases and relationships between them. The semantic and linguistic chunks correspond to Description Logic constructors. Problems and solutions for querying biomedical linked data with Romanian, besides English, are also considered in the context of GF.

From Abstract Syntax to Universal Dependencies

Abstract syntax is a semantic tree representation that lies between parse trees and logical forms. It abstracts away from word order and lexical items, but contains enough information to generate both surface strings and logical forms. Abstract syntax is commonly used in compilers as an intermediate between source and target languages. Grammatical Framework (GF) is a grammar formalism that generalizes the idea to natural languages, to capture cross-lingual generalizations and perform interlingual translation. As one of the main results, the GF Resource Grammar Library (GF-RGL) has implemented a shared abstract syntax for over 30 languages. Each language has its own set of concrete syntax rules (morphology and syntax), by which it can be generated from the abstract syntax and parsed into it. This paper presents a conversion method from abstract syntax trees to dependency trees. The method is applied for converting GF-RGL trees to Universal Dependencies (UD), which uses a common set of labels for different languages. The correspondence between GF-RGL and UD turns out to be good, and the relatively few discrepancies give rise to interesting questions about universality. The conversion also has potential for practical applications: (1) it makes the GF parser usable as a rule-based dependency parser; (2) it enables bootstrapping UD treebanks from GF treebanks; (3) it defines formal criteria to assess the informal annotation schemes of UD; (4) it gives a method to check the consistency of manually annotated UD trees with respect to the annotation schemes; (5) it makes information from UD treebanks available.

The Notion Of ˜Case From Traditional Grammar To Modern Grammatical Theories: A Critical Historical Review

The notion of case has been a controversial one, yet the grammatical terminology has survived right from traditional Grammar to the current grammatical theories. This paper critically examines the notion of case within different grammatical frameworks. Our interest is mainly on the role of syntax and semantics in case determination and the level of grammatical analysis (deep or surface) at which case is assigned. The paper looks at the notion of case as conceived in traditional grammar and the explores how the concept has been adapted to antecedent grammatical theories up to the Principles and parameters theory. The paper concludes that in all the grammatical models, Case has both syntactic and semantic relevance.

A GF miniature resource grammar for Tswana: modelling the proper verb

The Grammatical Framework (GF) not only offers state of the art grammar-based machine translation support between an increasing number of languages through its so-called Resource Grammar Library, but is also fast becoming a de facto framework for developing multilingual controlled natural languages (CNLs). For a natural language to share maximally in the opportunities that GF-based multilingual CNL support presents, it has to have a GF resource grammar. Tswana, an agglutinating Bantu language, spoken in Southern Africa as one of the eleven official languages of South Africa, does not yet have such a grammar. This article reports on the development of a so-called miniature resource grammar, a first step towards a full resource grammar for Tswana. The focus is on the modelling of the Tswana proper verb as it occurs in simple sentences. The (proper) verb is the morphologically most complex word category in Tswana, and therefore constitutes a notable contribution towards the development of a GF resource grammar for Tswana. The computational model is discussed in some detail, implemented and tested on a systematically constructed treebank.

A multilingual FrameNet-based grammar and lexicon for controlled natural language

Berkeley FrameNet is a lexico-semantic resource for English based on the theory of frame semantics. It has been exploited in a range of natural language processing applications and has inspired the development of framenets for many languages. We present a methodological approach to the extraction and generation of a computational multilingual FrameNet-based grammar and lexicon. The approach leverages FrameNet-annotated corpora to automatically extract a set of cross-lingual semantico-syntactic valence patterns. Based on data from Berkeley FrameNet and Swedish FrameNet, the proposed approach has been implemented in Grammatical Framework (GF), a categorial grammar formalism specialized for multilingual grammars. The implementation of the grammar and lexicon is supported by the design of FrameNet, providing a frame semantic abstraction layer, an interlingual semantic API (application programming interface), over the interlingual syntactic API already provided by GF Resource Grammar Library. The evaluation of the acquired grammar and lexicon shows the feasibility of the approach. Additionally, we illustrate how the FrameNet-based grammar and lexicon are exploited in two distinct multilingual controlled natural language applications. The produced resources are available under an open source license.