Objective:To compare how children who use either cochlear implants (CIs) or hearing aids (HAs) express English inflectional morphemes during conversation, i.e., with voice, with sign, or with both. A secondary objective was to investigate the relationship between morpheme use in pediatric CI users and their speech perception skills, length of experience with the device, and accuracy of phoneme production.Design:Group 1 consisted of 25 children who used CIs, and Group 2 consisted of 13 children who used HAs. All children were prelingually deafened and all used simultaneous communication. A 12 minute spontaneous conversation was elicited, transcribed and coded. Between group comparisons were performed to evaluate differences in modality and number of morphemes used. Additionally, use of morpheme endings was related to length of CI experience, accuracy of phoneme production, and closed-set speech recognition performance.Results:Children who had CI experience produced significantly more English inflected morphemes than children in the HA group. CI participants also expressed the inflected endings by using voice-only mode 91% of the time, whereas HA participants used voice-only mode 1% of the time. In the CI group, a strong relationship was found between number of morpheme endings used and speech recognition scores, length of CI experience and accuracy of phoneme production. The results of this study indicate that input from the CI facilitates children's ability to perceive and comprehend bound morphemes.