Existing work on the acquisition of syntax has been concerned mainly with the early stages of syntactic development. In the present study we examine later syntactic development in children. Also, existing work has focused on commonalities in the emergence of syntax. Here we explore individual differences among children and their relation to variations in language input. In Study 1 we find substantial individual differences in children's mastery of multiclause sentences and a significant relation between those differences and the proportion of multiclause sentences in parent speech. We also find individual differences in the number of noun phrases in children's utterances and a significant relation between those differences and the number of noun phrases in parent speech. In Study 2 we find greater syntactic growth over a year of preschool in classes where teachers' speech is more syntactically complex. The implications of our findings for the understanding of the sources of syntactic development are discussed.

中文翻译：

---

语言输入和子句法

现有的句法习得工作主要关注句法发展的早期阶段。在本研究中，我们研究了儿童后期的句法发展。此外，现有工作侧重于语法出现的共性。在这里，我们探讨了儿童之间的个体差异及其与语言输入变化的关系。在研究 1 中，我们发现儿童对多句句的掌握存在显着的个体差异，并且这些差异与父母讲话中多句句的比例之间存在显着关系。我们还发现儿童话语中名词短语数量的个体差异以及这些差异与父母话语中名词短语数量之间的显着关系。在研究 2 中，我们发现在一年的学龄前班级中，教师的言语在句法上更加复杂，句法增长更大。讨论了我们的发现对理解句法发展来源的影响。