The valid identification and description of language impairment in children who speak African American English (AAE) has been a major clinical challenge for over 30 years. This challenge centers on the issue of deficit versus difference for language features that contrast with Standard American English. The distinction between deficit and difference in identifying language disorders in child African American English speakers is the key to valid language assessment in AAE. Most syntactic targets in SAE are presumably invariable while many syntactic targets in AAE are variable. For example, the SAE target syntactic form for the copula is would be represented by He is bad . Whereas that same production in AAE might yield either He is bad or He_bad . Our research focuses on how one determines if a child AAE speaker who uses He_bad does so as a function of dialect, not impairment
