The effect of variable input on children's acquisition of null subjects

语言对我们生活的方方面面都至关重要，在学校学习中它绝对是核心。第一语言习得研究的目的是确定在给定的语言输入条件下儿童是如何习得母语的。研究表明，孩子们不仅仅是逐字逐句地模仿他们的输入；相反，他们会说一些父母说话中没有的形式，比如“他吃了它”或“我要抓住它”。此外，儿童接触到的语言输入是相当复杂的，因为话语并不总是与其潜在的表征相匹配。例如，在“你想去吗？”这样的句子中，说话者会根据不同的社会语境，省略前两个词，产生：“你想去吗？”，“想去吗？”。这个项目考察了后一种变量输入对儿童语言习得的影响。该项目的经验领域是获取与两种西班牙语（多米尼加西班牙语（DS）和智利西班牙语（ChS））中传统上被称为Null Subject Parameter的属性。ChS显示了无主语语言的特性，而DS显示了许多在其他非加勒比西班牙语变体中不常见的句法特性，包括明显的咒骂主语的可变使用，在主题连续性的上下文中更多地使用明显的代词主语，以及在疑问句中主语-动词（非）倒转的可变使用。通过比较儿童接触同一语言的两种变体时的习得模式，我们可以比较两种输入类型（如一致输入和可变输入）下特定语法结构的习得情况，同时保持语言的其他属性不变。这个项目将收集120小时的残疾儿童看护人和他们的孩子在一起玩耍和阅读时的自然语言，以及40小时的多米尼加成人之间的语言。录音和转录将被存档在CHILDES数据库（http://childes.psy.cmu.edu）中，供未来的研究人员使用，并将为学习非主流西班牙语方言的儿童的语言发展提供急需的数据，这在标准化测试、早期教育和语言障碍临床干预的背景下是重要的。该项目还将为研究生和本科生提供国际研究经验，他们将在多米尼加共和国收集数据。

Language is essential to almost every aspect of our lives and it is absolutely central to learning in school. The goal of first language acquisition research is to determine how children acquire their native language given the linguistic input to which they are exposed. Research has shown that children do not just imitate word-for-word their input; instead, they produce forms not found in their parents' speech, such as "He eat-ed it" or "I'm hang onto-ing it." Moreover, the linguistic input to which children are exposed is quite complex, as utterances do not always match their underlying representation. For example, in sentences like "Do you want to go?" speakers variably omit the first two words, producing: "You wanna go?", "wanna go?", depending on social context. This project examines the impact of this latter sort of variable input on the acquisition of language in children. The empirical domain of this project is the acquisition of properties related to--what has traditionally been called--the Null Subject Parameter in two varieties of Spanish: Dominican Spanish (DS) and Chilean Spanish (ChS). While ChS shows properties of a null subject language, DS displays a number of syntactic properties that are infrequent in other non-Caribbean varieties of Spanish, including variable usage of overt expletive subjects, higher use of overt pronominal subjects in contexts of topic continuity, and variable usage of subject-verb (non)inversion in interrogatives. By comparing acquisition patterns in children exposed to two varieties of the same language, we can compare acquisition of specific grammatical structures in the context of two input types (e.g. consistent input v. variable input) while holding other properties of the language constant. This project will collect 120 hours of naturalistic speech between DS caregivers and their children while they play and read together and 40 hours of Dominican adult-to-adult speech. Audio-recordings and transcriptions will be archived on the CHILDES database (http://childes.psy.cmu.edu) for use by future researchers and will provide much needed data on language development in children acquiring non-mainstream dialects of Spanish, which is important in the context of standardized testing, early education, and clinical intervention in the case of speech disorders. This project will also provide international research experience to both graduate and undergraduate students, who will collect data in the Dominican Republic.