英语学习者口语句法复杂性发展研究

摘要

本文横向考察了国内某重点大学英语专业四个年级口语句法复杂性的发展模式。句法复杂性包括句法多样化程度和句法复杂化程度，其中后者包括单位长度和子句密度（或内嵌度）两类。单位长度用T单位长度和子句长度指标测量；子句密度用T单位复杂性比率和从属句比率指标测量。研究发现，学习者的句法长度随年级的增加呈上升发展趋势，且发展速度较快；子句密度呈迂回式发展，三年级学习者在口语子句密度发展方面具有“高原效应”，呈现出大幅下降趋势；且长度指标的发展速度明显快于子句密度。%This research aims to investigate the developmental pattern of oral syntactic complexity by a cross-sectional study of four grades of English majors at a key university in China. Syntactic complexity includes syntactic variation and syntactic sophistication. The latter one includes unit length and clausal density （or degree of embeddedness）. Unit length is measured by indexes of T-unit length and clausal length. Clausal density is measured by T-unit complexity ratio and dependent clause ratio. The investigation reveals that the unit length of subjects＇ oral language increases linearly with grades at a high rate ; however, the clausal density develops curvedly with an obvious decrease in the third grade characterized by the ＂plateau effect＂. And the developmental rate of unit length is higher than that of clausal density.