for their assistance in collecting and analyzing the data. Objectives: The purpose of this study is to examine the developmental tendency of syntactic development from early childhood to old age. Methods: Normal developing children, adolescents, young adults, middle adults, and the elderly (N= 120) participated in the study. Fifty language utterances from each participant were taken from a semi-structured conversation. In terms of the characteristics on syntactic output, the number of syllables, postposition, suffixes, and functors per utterances were measured. In terms of the characteristics on syntactic length, mean length of utterance in morphemes (MLU-m), mean length of utterance in words (MLU-w), mean length of utterance in clutters (MLU-c), and mean syntactic length (MSL) were measured. In terms of the characteristics on syntactic type, the percent of simple sentence and complex sentence were measured. Results: Most of parameters increased from early childhood to adolescence significantly, then decreased in the age groups after young adults, and slightly increased in middle adults, and decreased in the elderly. Discriminant analysis showed the number of suffixes per utterance, the number of functors per utterance, MLU-m, and MSL were good discriminators between the age groups. Conclusion: The findings present syntax indicators that distinguish each age group in order to confirm the development of syntactic ability from the viewpoint of the whole life span.
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