*3.1. Accuracy*

We saw similar rates of response accuracy from interlocutors across both groups, with both Cena and Libras interlocutors identifying the correct target clip in 91% of cases. The similarity in these figures serves as a confirmation that the productions in response to the task were highly successful from a communicative standpoint. Correct comprehension tended to fail in cases of reversible transitive (such as *woman looks at man*) or ditransitive (*man throws ball to girl*) events or in non-agentive intransitive events (*ball rolls*). In transitive and ditransitive cases of communication breakdown, it was usually due to a need to disambiguate who was the subject and who was the object. We imagine that incorrect comprehension of non-agentive intransitive events may be because telling a friend or family member 'a ball rolled' with no additional information or context is a strange communicative interaction perhaps with the potential to confuse.
