Sentences can be enriched by considering what the speaker does not say but could have done. Children, however, struggle to derive one type of such enrichments, scalar implicatures. A popular explanation for this is that they do not know the appropriate alternatives to use to generate the implicature. Namely, children are unaware of the scalar relationship between some and all. We conducted a priming study with N = 72 children, aged 5;1 years, and an adult sample, N = 50, to test this hypothesis. Participants were exposed to prime trials of strong, alternative or weak sentences involving quantifier sentences or ad hoc expressions, and then saw an ambiguous target trial that they could choose to enrich. Consistent with previous studies, children were reluctant to derive implicatures. However, there were two novel findings. (1) Children responded with twice the rate of ad hoc implicature responses than adults, suggesting that the implicature was the developmentally prior interpretation for ad hoc expressions. (2) Children showed robust priming effects, suggesting that children are aware of the scalar relationship between some and all, even if they choose not to derive the implicature.