Design of Graphical User Interface 57

Information Structure (IS) is one of the fields of linguistic investigation that has been broadly handled in the history of linguistics. Virtually every research area-phonology, semantics, pragmatics, morpho-syntax has in one way or the other accounted for how the phenomenon is realised in the languages of the world. However, there is no unanimity among researchers with regard to finding a universal linguistic theory capable of accounting for the variation in IS strategies exhibited by languages. For this reason, it is still in debate whether IS belongs to grammar proper or to pragmatics or to any other linguistic component. On this issue, Erteschik-Shir (2007: 4) has this to say:

Within modern linguistic theories, the place of information structure in grammar is far from settled.

Within the Principles and Parameters theories (GB/MP), information structure is generally relegated to the peripheries, making it hard to express its central role with respect to syntax, semantics, and intonation in a systematic way.

Much of the work, which make a headway incorporate other linguistic components in its analysis as pointed out above. Therefore, a purely syntactic approach to IS is difficult to conceive. However, Schwabe and Winkler (2007:5) identify two central approaches to the study of IS, meaning and form.

i. The Formal View

ii. The Semantic-Pragmatic View

The formal view includes (a) the syntactic or feature-based account and (b) the phonological or prosody-based account. While the semantic-pragmatic view includes (a) the one-to-one mapping account of grammatically determined meaning onto

pragmatic meaning and (b) the underspecification account. Below is a brief highlight of the views.

2.1.2.1 The formal Approach: Syntax and prosody: This approach was developed by Chomsky (1971) and Jackendoff (1972) and has been argued within the Generative Grammar. Within this view, the central theme of the feature-based approach is that the information structural notions, topic and focus, are integrated into the formal system of language. According to the standard variant of this theory, a formal F(ocus)-feature is introduced at some level of the representation and causes the F-marked phrase to move to the specifier position of a corresponding functional focus head, which is projected in the left-peripheral domain of the sentence (see Rizzi, 1997, É. Kiss, 1998). The F-feature is translated at the phonological form (PF) into prominence according to specific phonological rules and at the logical form (LF) into a semantic representation.

Within this theory, information structural notions are directly and unambiguously represented in the syntactic component and translated at the two interpretive interfaces.

In the last two decades, the syntactic account of IS focuses on two themes: first, the definition and exact structure of the left periphery and secondly, whether the assumed structure and recursiveness of the left periphery is universal? This forms the main idea of Rizzi’s Split CP proposal. Rizzi’s (1997) analysis and other syntactic account of IS identify two main area in sentential structure where structural topic and focus positions are located. These are CP area (i.e. for languages that exhibit movement of focus within the left periphery) and the VP area. The recent developments within the MP such as the introduction of the notion of phase and other proposals which claim that focus operators move to a position at the left edge of ʋP lend support to the current syntactic assumption that displacement/dislocation is always to the left edge of the sentence or the left edge of the predicate phrase or ʋP phase. One of such proposals is presented by Drubig (2007:39) and is roughly schematised below:

The schema above is used to argue that an ordinary main clause is biphasal with internal and external peripheries to which the Split-CP layer in Rizzi’s sense applies⁵. The external periphery is above TP while the internal periphery is below TP and above ʋP. Schwabe and Winkler (2007), building on the suggestions of Butler (2003), argue that these functional peripheries are isomorphic. In other words, they show identical component projection at the edge of every phase with certain variations due to semantic difference between event and proposition related phases⁶. The proposal is among the evidence provided in support of the claim that topic and focus exist in both CP and ʋP areas. Further insight into this assumption is provided in Chapter 5 under the analysis of the structure of the CP layer.

Generally, the syntax-based approaches hinge on the hypothesis that IS notions (e.g.

topic and focus) are represented as formal features in the syntactic component of the generative system. Feature-annotated syntactic structures are interpreted on the two interface levels, PF and LF that make up the interfaces for AP and CI systems as

5 The proposal suggests that TopP-FopP array occurs both in COMP and in INFL targeting the edge of the phase.

6 Drubig (2007) used the structure of polarity, modality and force/mood projections as well as their different interpretations in eventive and propositional phases as evidence to argue that a sentence could be assigned more than one force against the traditional view that that every sentence represents a particular speech act type and therefore can have one and only one force component, which is located in COMP.

ForceP

VP ʋP

CP ForceP

TP tP CP

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represented by the T-model below (see Chomksy, 1995:168 and Schwabe and Winkler, 2007:11).

The claim presented above is called the two interpretive interface hypothesis and is formalised below:

(26) Two-Interpretive Hypothesis

The syntactic structure is interpreted at its interfaces, PF and LF.

Schwabe and Winkler (2007) note that the advantage of the two-interpretive interface hypothesis is that it is strictly modular and therefore a restrictive model of grammar.

However, its disadvantage lies in the fact that it has been driven by theory-internal rather than empirical considerations. In other words, the claim that phonology interacts with meaning only via syntax and vice versa might be empirically⁷ inadequate because it was observed that information structural phenomena may pose a challenge to this hypothesis since they seem to allow for a direct interaction between the different modules. Nevertheless, since the focus of this work is to determine the structure of the Igbo clause, a syntactic account of IS would help to determine the positions of Topic, Focus and question, and subsequently, yield the hierarchy of constituents in the Igbo CP domain. In a related manner, the prosody based account proposes that some movement operations are not feature-driven and do not occur in syntax, but are rather phonologically driven and occur in the phonological component⁸. Further developing this view, the advocates argue that phonological requirements trigger movement for different information structural effects; and that a direct correspondence exists between phonology and interpretation without recourse to syntax, to mention but a few.

7 The reader is referred to Riemsdijk & Williams 1986, Woodbury (1987), Winkler 1997) a.o.

8 Some of the related works as cited by Schwabe and Winkler are Zubizarreta (1998), Szendrői (2001), (2004), Erteschik-Shir (2007).

(25) Lexicon

(Spell-Out) Syntax

PF

Articulatory System

LF Intentional System

2.1.2.2 The Semantic Pragmatic Approach: The central idea of this interpretive approach is the assignment of discourse functions to syntactic and phonological constituents. It is therefore, concerned with the mapping of the formal linguistic structure onto the semantic structure. It interprets syntactically and phonologically marked focus or topic constituents, modelling their internal and sentence-external function. Thus, they regard focus and topic as semantic phenomena, design formal methods to model focus-background and topic-comment structures. If an approach takes the linguistic structure as its starting point, it is subsumed under the cover term semantic-based approaches. There are sub-variants of this approach (for details, see Schwabe and Winkler, 2007). Conversely, pragmatic based approaches take communicative and functional aspects of a sentence as their starting point and model a separate information structural component. In this case, the primary concern is the elaboration of pragmatically determined IS. This study is not based on interpretive approach since it would not help to achieve the objectives of the study which is to determine the structure and hierarchy of constituents within the layers of the clause and the various interactions therein.