Research Findings: Research suggests children from low-income environments have vocabularies that differ from those of their higher-income peers. They may have basic knowledge of many words of which children from higher income environments have acquired sub- or supra-ordinate knowledge. This study sought to determine if children from low-income environments frequently missed certain items on a standardized vocabulary measure and to investigate their response patterns on an experimenter-created assessment. In Experiment 1, response patterns of children from low-income environments on a standardized vocabulary test were analyzed to determine frequently missed items. In Experiment 2, a separate cohort of children from low-income environments was administered an experimenter-created protocol that included adapted testing formats which receptively and expressively tested frequently missed items and associated foils. Participants were able to demonstrate basic knowledge of many of the frequently missed items under at least one of the adapted testing formats. Practice or Policy: Results from both experiments provide insight into which vocabulary items were frequently missed and possible strategies children from low-income environments used to respond to them. Suggestions for further research into the use of the adapted testing formats with children from low-income environments are provided. (author abstract)