A long history of research has considered the role of iconicity in language and the existence and role of nonarbitrary properties in language and the use of language. Previous studies with Japanese-speaking children, whose language defines a large grammatical class of words with clear sound symbolism, suggest that iconicity properties in Japanese may aid early verb learning, and a recent extended work suggests that such early sensitivity is not limited to children whose language supports such word classes. The present study further considers the use of sound-symbolic words in verb-learning context by conducting systematic cross-linguistic comparisons on early exposure to and effect of sound symbolism in verb mapping. Experiment 1 is an observational study of how English- and Japanese-speaking parents talk about verbs. More conventionalized symbolic words were found in Japanese-speaking parental input, and more idiosyncratic use of sound symbolism was found in English-speaking parental input. Despite this different exposure of iconic forms to describe actions, the artificial verb-learning task in Experiment 2 revealed that children in both language groups benefit from sound-meaning correspondences for their verb learning. These results together confirm more extensive use of conventionalized sound symbolism among Japanese speakers and also support a cross-linguistic consistency of the effect, which has been documented in the recent work. The work also points to the potential value of understanding the contexts in which sound-meaning correspondences matter in language learning. (Contains 3 tables and 4 figures.)