A Contrastive Study Of Modal Verb Acquisition In Mandarin-Speaking Children With SLI And HFA

As a important linguistic research topic at home and abroad,modal verbs have been discussed not only in linguistic study but also in language acquisition research.There are numerous researches into the modal uses in normal children,but few studies have been conducted on the acquisition of modal verbs in children with specific language impairment(SLI)and children with high-functioning autism(HFA).Thus,based on previous studies,the current study aims to investigate the acquisition of modal verbs and modality functions in children with SLI and HFA and attempts to explore the similarities and differences between two types of children.To achieve the above goals,experiments are carried out to examine the production and comprehension of modal verbs in three groups of children: two experimental groups,composed of SLI and HFA children,respectively,and a control group of typically-developing age-matched(TDA)children.The experimental data are collected from two types of experiments,namely,the picture-elicited production task and the picture-selection comprehension task.The items tested in the current study are three modal verbs,the dynamic modal hui ‘know how to',the dynamic modal yao ‘want,desire' and the deontic modal gai ‘should',which have been acquired early by typically-developing children.The experiments have produced the following results.Firstly,both HFA children and SLI children have difficulty in the production of modal verbs,especially the deontic modal gai ‘should'.Secondly,SLI children perform worse in comprehending the modality functions of volition and obligation while HFA children perform worse in comprehending all of the three modality functions.The current study has made the following tentative analysis of the experimental results.(i)As for HFA children and SLI children,the syntactic and semantic complexity of modal verbs might cause difficulty in producing the modal verbs;the deficits in using deontic modals could be explained by the Modality Spectrum(Tsai2010)and the Derivational Complexity Metric(Jakubowics 2011).Thus,deontic modal verbs have a more complex syntactic deviation,causing difficulty for HFA and SLI children.(ii)The discrepant performance between SLI and HFA children in the comprehension task welcomes the semantic and cognitive explanation.As the modality functions of volition and obligation are likely to overlap with similar notions,the disturbance from the notion similarity may result in difficulty in comprehending the modals in question.As for HFA children,their impaired ToM development may hinder them from comprehending the modality functions.Although it is a preliminary research,the current study is of practical and theoretical value.Theoretically,the current study enriches the acquisition study of Chinese modal verbs.Practically,it will contribute to the diagnosis,intervention and treatment of SLI and HFA children.