In their first three years, children begin to maintain topics and add new information in conversation. In turn, caregivers create opportunities for language learning. Compared to children with no family history of autism (typical likelihood, TL), the younger siblings of children with autism spectrum disorder (ASD) are at elevated likelihood (EL) for both ASD and language delays. This study asked: (1) Do profiles of spoken language and conversational skills differ across groups? (2) Does spoken language relate to conversational skills? and (3) How does parent speech relate to child spoken language and conversational skills? Child spoken language, conversational skills, and parent speech were examined during toy play at home with three-year-old TL (n = 16) and EL children with ASD (EL-ASD, n = 10), non-ASD language delay (EL-LD, n = 21), and no delays or diagnoses (EL-ND, n = 37). EL-ASD children produced fewer intelligible utterances, and EL-LD and EL-ASD children produced shorter utterances than TL and EL-ND children. When utterances were intelligible, all groups were highly contingent to the topic. EL-ASD children were less likely than all other groups to add new information, and adding new information was positively associated with utterance length. Parents of EL-ASD children had fewer opportunities to respond contingently. However, all parents were highly topic-contingent when child speech was intelligible, and parent speech complexity varied with child language and conversational skills. Findings highlight strengths in conversational skills for EL-ASD children during toy play with parents and show that children and caregivers together shape opportunities for developing language and conversation.