The current study analyzed individual mechanisms of language gains following the Solomon et al. (2014) randomized control trial (RCT) of the Play and Language for Autistic Youngsters (PLAY) Project, a DIR/Floortime based early intervention program for children with autism spectrum disorder. 80 parent-child play interactions from the original RCT were analyzed to assess the relationship between various forms of parental question input, as taught in PLAY parent trainings, and child language measures. While high parental question input did correlate with high child language measures, one targeted intervention component, parental Asked/Answered question input, did not increase following parent training and did not improve child language measures. We consider other mechanisms responsible for successful child language gains following PLAY intervention.