Advances in the Sign Language Development of Deaf Children

Barbara Shaffer

While it is important to continue to study cognitive development in children, we can never fully understand how children construe their worlds. Certain linguistic competencies, however, do provide a window into the child's developing mind and therefore contribute to our overall understanding of child development. Mastery in the use of modal terms (e.g., "have to," "should," "can") is a major linguistic feat, one that suggests much about a child's cognitive development and social awareness. This chapter explores the emergence of modal terms in deaf children. It focuses primarily on two types of modality: agent oriented and epistemic. Agent-oriented modals describe conditions placed on main clause agents (e.g., "John must go to the doctor"), while epistemic modals convey the speaker's beliefs regarding the truth of a proposition ("John could be at the doctor").

Modal utterances of both types are high in speaker subjectivity; that is, they actively place speakers within their own discourse. In addition, epistemic modals refer to the mental state of the speaker. Research is beginning to show that competent use of epistemic modals, in particular, requires specific cognitive skills, including theory of mind reasoning. Regardless of the language, in order to competently use words that express degrees of certainty, children must be aware that they have unique beliefs and desires that can be conveyed to others (see LópezOrnat, Férnández, Gallo, & Mariscal, 1994; Moore & Frye, 1991; PérezLeroux, 1998).

While there are identifiable cross-linguistic tendencies in the acquisition of modal terms, deaf children are faced with the unique situation

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