DESARROLLO DEL MODELO TEÓRICO DE CALIDAD DE VIDA

In the thesis, I also explore the lexical and grammatical relationship in the bilingual child’s development of Malay and English. Therefore, in this section, studies investigating lexical and grammatical relationship in child language acquisition, both in monolingual and bilingual studies, are reviewed. Research on monolingual children has found a close relationship between lexicon and grammar, particularly in the early stages of acquisition. Based on English data, groundbreaking research such as Bates, Dale and Thal (1995), Bates and Goodman (1997), Bates and Goodman (1999), Fenson, Bates, Dale, Thal and Reznick (1994), Dale, Dionne, Eley and Plomin (2000) and Dionne, Dale, Boivin, & Plomin (2003) show a high correlation between vocabulary size and the development of grammar.

In their study of 1,803 English L1 children, Bates et al. (1995) reported a tight relationship between the size of the children’s lexicon and the onset of grammar. Their findings indicate three level of development; firstly, word combinations appear when the vocabularies fall between 50-200 words. Secondly, verb morphology emerges when the vocabularies are within 400-600 words and finally, sentence complexity are observed to increase significantly when the children’s vocabulary exceeds 400 words. The developmental nature of lexicon and grammar in their study is illustrated in the following graphs:

Figure 3.2. Percentage of subjects producing word combinations as a function of vocabulary size on the MacArthur CDI toddler scale, taken from Bates et al. (1995, p.39).

Figure 3.3. Grammatical complexity score as a function of vocabulary size on the MacArthur CDI toddler scale, taken from Bates et al. (1995, p.39).

Based on the findings, Bates et al. (1995) suggest, “grammatical development depends upon the establishment of a critical lexical base. Indeed, different grammatical events may each depend upon a different lexical base e.g. word

combinations emerge in the 50-100-word range; verb morphology emerges in the 400- 600-word range” (p.11). Pertaining to the word range, Marchman and Bates (1994) proposed the notion of critical mass hypothesis; according to this notion, the morphological acquisition is contingent on the child’s acquisition of words, “most strongly after the number of items in a child’s vocabulary reaches a critical mass”(p.346). Marchman and Bates state that there seems to be a strong continuity between lexical and grammatical development. Bassano, Laaha, Maillochon, and Dressler (2004) support this notion, stating that “developments within morphosyntax are triggered by an increase in the size of the lexicon beyond a given level, thus providing support for the interdependence of lexical and morphosyntactic developments” (p.36).

The lexical-grammatical relation is also observed in other L1 acquisition, for example Italian (Caselli et al., 1995; Caselli, Casadio, & Bates, 1999), Hebrew (Maital, Dromi, Sagi, & Bornstein, 2000), Icelandic (Thordardottir, Weismer, & Evans, 2002), and Spanish (Jackson-Maldonado, Thal, Marchman, Bates, & Gutierrez-Clellen, 1993; Jackson-Maldonado et al., 2003).

For bilingual children, studies investigating the lexical grammatical relationship show that the bilingual children’s grammatical abilities are correlated with the size of the lexicon in the specific language. For example, the findings reported by Marchman, Martinez-Sussman, and Dale (2004) in their 113 Spanish-English bilingual participants is that the grammatical ability in Spanish is correlated by the size of Spanish lexicon and likewise, the grammatical ability in English is correlated with the size of the participants’ English lexicon. Conboy and Thal (2006) also report that the use of relational and function words in English-Spanish bilinguals are dependent on the growth in of vocabulary in each language. Similarly, the findings in Simon-Cereijido and Gutiérrez-Clellen (2009) also demonstrate high correlations between vocabulary and grammar in 196 Latino five-year-olds. Other than Spanish- English language pair, French-English bilinguals also exhibit similar developmental pattern; French grammar is influenced by the size of French lexicon and vice-versa (David & Li Wei, 2005).

In all these bilingual studies, the researchers could not find any cross-language correlations. The development of grammar in bilingual children is found to be proportional to the growth of the lexicon within the same language. Thus, they interpret the results as supporting the autonomous development of the two languages (De Houwer, 1990; Meisel, 1989). However, I believe more studies on different

language pairs are needed to understand the relationship between the emergence of grammar and the size of the lexicon in bilingual children. Specifically, the issues of mixing and code switching need to be highlighted with regard to the lexical- grammatical relationship in BFLA. Therefore, this thesis aims to address this gap by examining the correlation between lexicon and grammar in Malay and English bilingual child, hence shedding light on this issue.

In analysing the grammar-lexical association, I also analyse the bilingual child’s composition of lexicon in Malay and English (this will be discussed in Chapter 5 Morphological development). Previous studies in L1 monolingual children have shown that nouns are the earliest and predominant lexical item acquired by children; Gentner and Boroditsky (2001) termed this phenomenon as ‘noun-dominance’.‘Noun- dominance’ phenomenon is supported by many studies, for example Fenson et al. (1994) report that nouns tend to dominate children’s early words. Similarly, studies conducted on L1 children acquiring other languages such as Turkish (Gentner, 1982), Spanish (Jackson-Maldonado, Thal, Marchman, Bates, & Gutierrez-Clellen, 1993), and French (Bassano, 2000) also indicate the early appearance and strong presence of nouns in early lexical acquisition. In bilingual acquisition, initially, Itani-Adams’ (2013) Japanese-English bilingual child exhibited higher usage of nouns in both Japanese and English. The child began learning the words in both languages with nominals, which is consistent with the ‘noun-dominance’ concept. However, in Japanese, Itani-Adams noted that the child increasingly continued using verbs that at age 4;7, the number of verbs becomes greater than nouns. So, for Japanese, the child began with noun-dominant and later on, her lexical acquisition shifted to become verb- dominant. For this thesis, we will see later in the analyses whether the Malay-English bilingual child acquires nominals first or some other lexical categories in her lexical acquisition

In this section, I have provided a review of studies related to grammar and lexical development in the monolingual and bilingual acquisition. In what follows, studies on the acquisition of plurality in FLA and BFLA is discussed.