Bilingual Children's Lexical Development: Factors Affecting the Acquisition of Nouns and Verbs and Their Translation Equivalents

Bilingual children's early lexical development so far has been part of the ongoing debate whether children start out with one system (Volterra & Taeschner 1978) or whether they develop two separate systems from early on (De Houwer 1990, Meisel 1994). In relation to bilingual children's lexical development, the debate has centred on the occurrence of cross-language synonyms or translation equivalents. According to Clark's (1987) principle of contrast, each word in the lexicon of the monolingual child must have a distinct meaning and accordingly, synonyms of the same item are not accepted. If this principle also holds for bilingual acquisition, bilingual children should not accept translation equivalents. However, both Pearson et al. (1995) and Quay (1995) show that translation equivalents occur from very early on and in some cases, in close succession. This finding is more in line with the separate system hypothesis, however, it raises wider issues on how bilingual children represent words in different language contexts to build up concepts of the words that they learn, whether they are able to link translation equivalents from early on and whether particular cross-language features facilitate early word learning. Research on adult bilinguals has shown that particular groups of words and their translation equivalents have a closer relationship and are translated faster as a result. In particular, Kroll & Stewart (1994), Kroll & de Groot (1997) and van Hell & de Groot (1998) have shown that there is an effect of form similarity, such that nouns that are similar in sound and spelling are translated faster in both translation directions. This effect has been explained by the conceptual feature model (Kroll & De Groot 1997) which suggests that form similar words have a feature overlap in their conceptual representations in the two languages. These findings have been found to be significant for bilingual children's developing representations. Schelletter (2002) reported on the early lexical development of nouns in a German/English bilingual child and also conducted a translation study with a group of school-age German/English bilingual children. Form similar nouns were found to be translated faster by the children and were also found to be more frequent among noun tokens used with a translation equivalent in the case study. The present study addresses the question whether the previous findings on form similar nouns can be also be extended to the class of verbs. For verbs, form similarity should also result in a conceptual feature overlap between verbs and their translation equivalents, on the other hand, verbs have been found to be tied in more with grammar (Schelletter et al. 2001). This could affect the speed of translation of verbs, as well as the acquisition of early verbs.