Social deficits have been implicated in the language delays and deficits of children with autism (ASD); thus, the extent to which these children use language input in social contexts similarly to typically developing (TD) children is unknown. The current study investigated how caregiver input influenced the development of "wh"-question comprehension in TD children and language-matched preschoolers with ASD. Children were visited at four-month intervals over 1.5 years; mother-child play sessions at visits 1-2 were coded for maternal wh-question use. At visits 3-5 children watched videos in the Intermodal Preferential Looking paradigm, to assess their comprehension of subject and object "wh"-questions. Mothers' use of "wh"-questions with verbs and complex "wh"-questions positively predicted "wh"-question comprehension in the TD group; in contrast, mothers' use of "wh"-questions with "be" as the main verb negatively predicted "wh"-question comprehension in the ASD group. Thus, TD children and children with ASD appear to use their linguistic input differently.