Specific language impairment as principle conflict: Evidence from negation

In this paper I will present the results from an experimental study designed to assess a group of SLI childrenʹs ability to judge the grammaticality of a range of negative constructions. In light of this data, two proposals relating to the underlying nature of SLI will be considered. The two proposals differ with respect to whether they see SLI childrenʹs language as reflecting a broader range of grammatical options (cf. Rice and Wexler, 1996; Van der Lely, 1998) or in fact two separate grammars, each of which specify a different range of grammatical options (cf. Davies, 1998). I will argue that my data clearly support the latter of these two options, suggesting that for the SLI child the appropriate form is sometimes ungrammatical.