First words : communicative development of 9 - to 24-month-old Thai children

Abstract

This study aims to investigate the phonological and lexical development of Thai children from 9 to 24 months of age. First language acquisition is a complex phenomenon, which involves not only universal and language specific factors, but also other factors including individual variation, individual preference, and the characteristics of the parental input. In relation to phonological development, it was found that children's productive ability is restricted in its phonological characteristics i.e. some sounds are produced more frequently than others; Stops > Nasals > Continuants > Fricatives in initial consonants; /a/ > /i/ > /u/ > /O/ > /x/ > /o/ > /e/ > /U/ > /q/ in monophthongs; Mid > Falling > Low > High > Rising in tones, and primary accented syllable > secondary accented syllable/s > unaccented syllable/s. Moreover, simpler combinations of sounds are produced before more complex ones such as, CV > CVV > CCV in open syllables, CVC > CVVC > CCVC in closed syllables, C > CC in consonants, and V > VV in vowels. In comparison to proportions of sounds in adults{174} speech it was found that children's phonological characteristics gradually develop toward those of adults (Hanpanich 1993). In relation to lexical development, it was found that children start to acquire their first word at around 9-15 months and have two distinctive rates of lexical acquisition; gradual and rapid. The duration of "the lexical explosion period", directly determines the amount of items children acquire at 24 months of age. In terms of lexical categories, it was found that, syntactically "Content Words" are acquired earlier and in greater number than "Function Words", and semantically "Nominals" are acquired earlier than "Verbals" and "Relations". In addition, it was found that comprehension normally precedes production in first language acquisition. However, during the period of "vocabulary explosion", it is possible that children could imitate some particular items before understand their meaning. The investigation of the relationship between parental input and children{174}s first words revealed that there was not a strong association between input and first words produced by children. The results suggest that children's attention to the input might be another possible factor to account for first language acquisition