Acquisition of Syntax in
Diane Lillo-Martin & Deborah Chen Pichler
There are at least two reasons to be interested in the acquisition of syntax in sign languages. One is in order to see the development of language in the deaf child—the process by which deaf children come to determine how their language operates. A second is to learn about the nature of language, thereby informing linguistic theory. By studying how deaf children acquire the syntactic structure of their language, we can test theories of language and language acquisition. We concentrate on the latter goal in the present chapter.
It is important for linguistic theory to consider data from the acquisition of sign languages. Generally, linguistic theory is developed on the basis of data from spoken languages only—and often, primarily on the basis of English and other Indo-European languages. Languages with distinct structures—particularly, languages employing a distinct modality—are crucial testing grounds for such theories. When linguistic theory is concerned with those properties that hold across all languages, its proposals should hold for sign languages as well as spoken languages. If some proposed universal does not hold for sign languages, the question should be asked whether there is an explanation for this gap as a modality effect. That is, is there some characteristic of the manual-visual modality as opposed to the oral-aural modality that explains why one group of languages, but not the other, displays this property (i.e., modality effect)? If not, the status of the purported universal as a true linguistic universal is threatened (Sandler & Lillo-Martin, 2005).
As an example, let us consider the tendency for signs to be monosyllabic yet multimorphemic (Brentari, 1995). What this means is that