语义子集难题与“是”的一语习得

The Semantic Subset Principle and the Acquisition of Shi(Be)in Mandarin

在汉语中,当“是”出现在动词短语之前时,句子允许“焦点”和“确认”两种解读。焦点解读具有排他性,语义更强,在真值条件上是确认解读的一个子集。这种情况下,儿童可能面临语义习得的子集难题。语义子集原则认为,语言习得机制会引导儿童先假定句子只有子集解读,再通过语言输入中的正面证据习得母集解读。采用真值判断任务对56名汉语儿童理解“是”的研究发现,5岁以前儿童只能得到“是”的焦点解读,符合语义子集原则的预测。儿童不能得到“是”的确认解读可能是因为表征该解读的句法投射层在该阶段的语法中缺失。

In Mandarin Chinese,when shi(be)occurs in the preverbal position,the sentence is subject to two kinds of interpretation:focus and assertion.The focus reading,which encodes exclusivity,is stronger than the assertion reading,as the truth conditions of the former constitute a subset of those of the latter.Thus,children acquiring the semantics of preverbal shi might be confronted with a subset problem.To solve the problem,the Semantic Subset Principle hypothesizes that children initially assume that the sentence only has subset reading,and then they acquire superset reading through positive evidence.Using the truth value judgment task,the present study reveals that Mandarin children have only acquired the focus reading of shi before 5,which is the subset reading relative to the assertion reading,confirming the prediction of Semantic Subset Principle.We further offer a discontinuity account of young children’s insensitivity to the assertion reading of shi,that is,the functional projection AssertP,which is responsible for the assertion reading,is absent in the early child grammar of Mandarin.