It is well documented that mothers often respond to infant vocalizations with verbalizations and these responses may encourage behaviors important to mastering speech and language. However, maternal utterances unrelated to infants' vocalizations and mothers' responsive actions may also serve predictable and relevant functions within mother-infant interactions. In this study, we explored the nature of maternal utterances deemed non-responsive to infant vocalizations by dividing them into five mutually exclusive categories (comment on ongoing activity, comment on new infant action, game/routine, and redirect). Additionally, we investigated maternal actions that were contingent upon the preceding infant vocalization. Contingent actions occurred within three seconds of and were relevant to the preceding vocalization. Maternal actions included head nods, comfort behaviors, object-related behaviors, increases in proximity, repositioning, none and irrelevant behaviors. We investigated responsive actions that occurred with maternal responsive utterances, non-responsive utterances and silence. Video recordings of thirty five mother-infant interactions (four-14 months of age) were used for analysis. Results revealed mothers often commented on an ongoing activity rather than responding contingently to infants' vocalizations. Mothers were more likely to verbally redirect the behavior of older infants than younger infants. Object-related nonverbal responses were common across all groups. Nonverbal behaviors also showed reliable patterns. Mothers rarely produced head nods with silence or non-responsive utterances; however, head nods frequently co-occurred with verbal responses. Finally, mothers combined actions with verbal responses more often than with verbal non-responses or maternal silence. In conclusion, mothers responded to infant vocalizations with appropriate verbal behaviors and predictable responsive actions.