Purpose: The purpose of this assessment-focused clinical focus article is to increase familiarity with African American English (AAE)-speaking children's pattern of language use in third-person singular contexts and to discuss implications for speech-language assessments of developing AAE-speaking children. Method: The clinical focus draws on descriptive case study data from four typically developing child speakers of AAE who are between the ages of 3 and 5 years. The children's data from three different sources--sentence imitation, story retell, and play-based language samples--were subjected to linguistic analyses. Results: The three sources of linguistic data offered different insights into the children's production of -"s" and other linguistic patterns in third-person singular contexts. Conclusions: This study underscores the importance of exploring developing child AAE from a descriptive approach to reveal different types of information about patterns of morphological marking in different linguistic contexts, which is crucial in assessing developing AAE. Implications for language assessment are discussed.