CHAPTER ONE BACKGROUND TO THE STUDY 1.0 Introduction Learning to speak is one of the most significant and visible achievements of early childhood. The acquisition of language ‘is doubtless the greatest intellectual feat any one of us is ever required to perform’ (Bloomfield 1933:29). The major concern of language acquisition study is to know how children acquire their first set of words. For us to also understand adult linguistic knowledge, we need to trace its development from the early years. To understand a little more about how language is acquired by the child is to move a step forward in unravelling the complexities of language (Kessler, 1971:7). Considering the complexities involved in language acquisition, there is a great deal that we still need to know. Of all the young child’s startling accomplishments, none is as impressive and mysterious as his entrance into the world of language (de Villiers & de Villiers, 1979). Tamis-Lemonda and Rodriguez (2008) state that the entry of children into “formal language” is one of the most heralded achievements of early development. Learning a first language is something almost every child does successfully, in a matter of a few years and without the need for formal lessons, (Pinker, 1995). Language acquisition is the process by which the ability to use language develops in humans; it enables man to develop language use. It is a natural human activity. Language acquisition begins very early in life and research has shown that some children 2 start talking as early as from four to eight months (Brown 1973, Cook, 1979, Dromi 1987, and Surakat 2001). The acquisition process begins logically with the acquisition of the sound patterns of the language. What a child learns in the course of language acquisition is not a set of utterances, but a set of rules for processing utterances (Slobin 1974:19). Pinker (1994a:2) further states that once acquired, a language is not a fixed list of sentences but a combinatorial algorithm allowing an infinite number of new thoughts to be expressed. Language acquisition is indeed a complex process. After discovering the meaning of certain words, the child has to determine the complex ways in which words are combined to form sentences; he has to determine the frame in which the verbs in the language occur. Hróarsdóttir (2003:116) says that evidence from human language studies show that children learn very complex phenomena in a relatively short period of time during their first language acquisition. The researcher’s interest in language acquisition is aroused by the knowledge that understanding the grammar of the young child means gaining a better insight into the nature of grammar in particular and language as a whole. To date, few studies exist on language acquisition in Nigerian languages and Yoruba in particular. Furthermore, very few researches on the acquisition of Yoruba syntax have been carried out. This study is also predicated on the fact that to date, as far as we know, no comprehensive study on the acquisition of Yoruba argument structure has been undertaken. The study focuses on the acquisition of the argument structure by Yoruba- speaking children. We adopt the generative theory approach and we precisely use the 3 Minimalist Programme (Chomsky, 1993 1995, 1998, 1999, 2000) as our framework. The study deals with the nature of developmental sequence leading to linguistic competence in Yoruba argument structure. From a broad range of data, this study shows that verbs have highly different argument structure properties. The study examines how children acquire predicate argument structure in the Yoruba language. The research also examines the development of verb meaning and syntax. The study looks at the acquisition of transitive (TR) and intransitive (INTR) verbs in Yoruba. We also undertake the study of the acquisition of null arguments and complex predicates. What follows is an exploratory study of the acquisition of Yoruba argument structure. 1.1 Statement of the Research Problem Language is a complex skill learnt by children. The ultimate goal of any theory of acquisition and research on acquisition in particular, is to explain how the child, within a very short period of time and without any formal tutoring, acquires mastery of his native language. Despite the Chomskyan position that certain aspects of language, such as basic semantic categories, might be ‘innate’, and that this might facilitate the acquisition of syntactic structure (Demuth, 1998:2), each language has its own peculiarities captured by the parameters. This brings out the need to study the acquisition of Yoruba argument structure. We set out to investigate how Yoruba argument structure are acquired by children between the ages of fifteen (15) to sixty (60) months. We intend to find out how Yoruba 4 children move from a state of no verb, no arguments and no argument structure to a state of mastery of verbs and the argument structure. 1.2 Objectives of the Study To investigate the stated research problem in 1.1 above, the study relies on the following objectives: 1. To examine the composition of early lexicon of the Yoruba child. 2. To examine the order of acquisition of Verb-Noun argument structure by the Yoruba child. 3. To examine acquisition of null arguments in Yoruba. 4. To examine how children acquire transitive and intransitive verbs in Yoruba. 5. To examine the nature of overt arguments acquired by the Yoruba child. 6. To know the stage at which the Yoruba child acquires complex predicates. 1.3 Research Questions Through careful analysis of the data collected, the study provides answers to the following research questions: 1. What is the composition of the early lexicon of the Yoruba child? 2. What is the order of acquisition of Verb-Noun argument structure by the Yoruba child? 3. How are null arguments acquired in Yoruba? 4. How do children acquire transitive and intransitive verbs in Yoruba? 5. What is the nature of overt arguments used by the Yoruba child? 5 6. At what stage does the Yoruba child start to acquire complex predicates? 1.4 Justification of Study This study is an investigation into the acquisition of the argument structure of Yoruba children. The acquisition of argument structure has long been a topic of interest in the language acquisition literature, and has continued to be one hotly debated today (Demuth 1998). However, not much has been done on this area of research as it affects Yoruba language. To the best of our knowledge, only few studies have been carried out on the acquisition of Yoruba as a first language. Such earlier studies include Ajolore (1974), Onidare (1983, 1985) and Oyebade (1990). Furthermore, to the best of our knowledge, no documented or coherent study on the acquisition of Yoruba argument structure exists. It is this gap that we intend to fill through the present research work. The verb constitutes a universal and very important lexical category (Robins 1966, Hopper & Thompson 1984, Langacker 1987, Uziel-Karl 2001). Awobuluyi (1979:114) says that verbs play a central role in sentences and that they are almost always present in sentences. Verbs especially play a very important role in language structure, in linguistics form-function relations, and in processes of language acquisition and language development (Uziel-Karl 2001). Argument structure is a very important aspect of verb knowledge. Since argument structure provides a good template for the understanding of how verbs relate with nouns in the process of language acquisition, we therefore consider it as the appropriate theme for this study. 6 The properties of each language influence the acquisition of the language and its argument structure in particular. According to Clark (2002:2) ‘since languages differ, their acquisition might also be affected by the properties of each language’. The child that is acquiring Yoruba will have to learn the syntactic category of words in the language and also more importantly learn the sub-categorization of verbs in the language. A verb in Yoruba and its equivalent in English could be realized differently. The reason for this is that equivalent verbs in these languages would have different patterns in projecting their arguments. For example, the verb ‘love’ in English subcategorizes for its object as in Olu loves you. The closest equivalent to this form in Yoruba is Olú fẹ́ràn rẹ which may not have the same meaning as Olu loves you. This same sentence is rendered as Olú ní ìfẹ rẹ which translates as ‘Olu has love for you’. Issues like these present good reasons for this study, as we cannot rely on studies in other languages to capture the peculiarities of the Yoruba language. The study proposes an insight into the mental processes of the child acquiring Yoruba argument structure, as each stage indicates the level of cognitive development of the child. We hope the research work will shed more light on the processes of child language acquisition. It will also examine the influence that parental input has on the child’s acquisition of argument structure. The work has implications not only for language acquisition and argument structure, but for the theory of grammar in general. For a linguist to have a full grasp of linguistic knowledge or competence, it is important to have a good knowledge of the processes associated with how it evolved. 7 The findings of this study will expose the development of argument structure of the Yoruba child and also the processes involved in language acquisition. Thus, we hope the study will have specific implications for the sequencing of structures in the preparation of language teaching materials. For instance, in preparing the language teaching syllabus, the curriculum designer would know how to sequence the topics, e.g.