Halliday and Webster (2009) define language as a kind of semiotic system which is based on grammar and characterized by stratal organization and functional diversity - both of which combine to form a semiotic of higher-order consciousness the basis for the human activity of meaning. Such a combination is deemed possible through clause complexing. Clause complexing is a component of the logical metafunction of language, which in turn belongs to the broader ideational metafunction of language. It refers to the relations that exist between clauses in a sentence. These relations are of two types, taxis and logico-semantics (Halliday, 1994, p. 373). This study in particular concerns itself with logico-semantics via the nature of the logical and semantic relationship between clauses.
Halliday (1994) and Gerot & Wignell (1994, p. 21) argue that whereas taxis can be divided into parataxis and hypotaxis, the logico-semantic relationships are of two broad kinds: expansion (comprising extension, enhancement and elaboration) and projection (comprising locution and idea) (cf. Halliday, 2004, pp. 376- 377). Saragih (2008, p. 45) postulates that logical meaning is a part of ideational meanings which is devoted to the clause complex hence logical function occurs in a clause complex.
Several studies have been carried out on logico-semantic relations and clause complexing: Rukmini (2010) analyzed the logico-semantic relation of clauses complexes in the abstracts of the final project reports produced by the English Department Students of Semarang State University. She found that the clause complexes made in the abstracts were of both parataxis and hypotaxis relation. The logico-semantic relations that were prevalent included elaboration, extension, enhancement and idea, while the locution projection was not found at all.
Srinon and White (2011) analysed Thai university students' essays in a longitudinal genre based course at a Thai government university in 2007. In this study, the researchers demonstrated how selected students presented their clause complexity which is related to, for example, inter-clausal relations (logico-semantic relation), coordination (parataxis) and subordination (hypotaxis). The results of the analyses indicated that the selected students showed a positive trend of developments in the use of semantic relations in their later texts. They included rich conjunctive relations and lexical resources in their later texts compared to the pre-test texts.
Brisk and Rosa (2014) did a research on emergence of logico-semantic relations in children's written language focusing on additive extension and enhancement relations. They realised that initially, connected clauses followed a temporal organization following the order of things in the world (cf. Kress, 1982) and that the default connective used was either temporal or causal. Temporal enhancement relations appeared first, followed by reason, condition, place, purpose, manner, and concession. They further found out that in early childhood, written clauses are often singular or joined by additive connectives. Temporal clauses were usually the first dependent clauses to be used and were often in a marked Theme position in the sentence. Brisk and Rosa realised that students made numerous attempts at using clause-complexes in their writing and that the types of relations varied in relation to the particular genres the students were encouraged to write. Performance differed depending on the grade level and genre. They also realised that students were more likely to write paratactic clauses rather than hypotactic clauses and that the conjunction 'and' was the default choice, especially when students wrote their uncoached personal recounts (cf. Christie, 2010, 2012; Christie & Derewianka, 2008).
Sulistyaningrum and Rasyid (2015) investigated the kinds of taxis and logico-semantic relation of students' presentation in Acceleration Program of SMA Labschool Jakarta. They analysed the meanings represented in clause complexes basing on the concept of relationship between clauses suggested by Halliday (1994, p. 373).
In their study, it was observed that the clause complexity in the acceleration students' presentation was varied. In the first group consisting 4 female students, almost all kinds of taxis and logico-semantic relation were found in their presentation, except hypotactic extension. In correspondence with the first group, the second group consisting 4 male students, produced all kinds of relation except locution. From all groups the type of taxis and logico-semantic relation that mostly arose was paratactic elaboration. Their analysis of meaning revealed that the dominant meaning was addition which appeared from extension.
Alaei and Ahangari (2016) carried out a study that aimed at determining how ideology or opinion is expressed in Joseph Conrad's Heart of Darkness and what kind of lexico-grammatical strategies are used in the first part of the novella to convey the author's ideological meaning. They investigated the ideational meaning by focusing on the lexico-grammatical choices in the transitivity system of the structure of the clauses and identified the metafunctional patterns of ideation found in the lexico-grammar of Joseph Conrad's Heart of Darkness.
The studies presented above lay a basis for research on logico-semantic relations. However, this study is concerned with the fact that they generally investigated all relations, taxis and logico-semantic, hence paying little key attention to the elaborative function of the conjunctive form. Moreover, the afore-presented studies majorly investigated and analysed written language. This study departs from the studies above by virtue of it relying on the spoken texts for data. It is also worth noting that this study investigated data from EkeGusii, a Bantu language which, according to the researcher's knowledge, has received little research attention in the area of logico-semantic relations.
Different terms have been used to refer to elaboration as a logico-semantic relation. They include 'explanation' (Kong, 2006 and van Leeuwen, 2005); 'exposition' (Martinec & Salway, 2005 and Unsworth, 2007); 'exemplification' (Kong, 2006; Martinec & Salway, 2005 and Unsworth, 2007); 'specification' (Djonov, 2005; Kong, 2006 and van Leeuwen, 2005). All these allude to elaboration as a logico-semantic relation; a relation in which a component is used to give more information or detail on a preceding component - a component is shifted in its degree of abstraction to make it more concrete, from more general to more specific. A component is elaborated by detail description, exemplification, clarification, or restating.
It is arguably true that elaboration is enabled in texts through the use of clauses, which create texts, (Halliday, 1981, p. 44; Martin & Rose, 2003). According to Halliday, a clause "has itself evolved by analogy with the text as model, and can thus represent the meanings of a text in a rich variety of different ways". Halliday and Webster argue that a clause is not just a constituent of the text but it is also the actualization of the text, inheriting properties from the text-as-model which is, itself, realized in relation to the context of situation (Halliday & Webster, 2009, p. 6). It is seen as a lexicogrammatical entity whereas a text is seen as a semantic entity (cf. Tam, 2013).
According to Halliday and Matthiessen (2004) and Thompson (2004) the central source for making meaning is the clause. Eggins (2004) argues that the term "clause" itself is called clause complex. Setial, Sutjaja, Saragih, & Putrayadnya (2009, p.1) on their part state that clause or clause simplex equals simple sentence in formal grammar and clause complex equals complex sentences. When two or more clauses are combined they produce a larger unit, called a clause-complex. This corroborates with Tarn (2013) who defines a clause complex as "a logical combination of clauses; it is a logico-semantic unit above the clause." These clauses "are linked to one another by means of some kind of logico-semantic relation" (Halliday & Matthiessen, 2004, p. 363). The interdependence among clauses is usually signalled by conjunctions (Eggins, 2004; Thompson, 2004) which in this study are referred to as conjunctive forms or elements. Clause complexing can result to elaboration, extension, or enhancement thus there is need for one to be keen on the exact logico-semantic relation they intend to render.
Clause complexing cannot be achieved with disregard to cohesion - the way sentences, written or spoken, are bound together in forming a text that has meaning (Finch 2000, p. 210; Halliday and Hassan 1976, p...