To acquire language, learners have to map the language onto the environment, but languages vary in terms of how much information is present within the language to constrain how the sentence relates to the world. We investigated the conditions under which information within the language and the environment is combined for learning. In a cross-situational artificial language learning study, participants listened to transitive sentences and viewed two scenes, and selected which scene was described by the sentence. The language had free word order, and varied in terms of whether or not it contained morphosyntactic information in order to define the subject and object roles of nouns in the sentence. We found that participants were able to learn information about word order and vocabulary from each language, demonstrating that information within the language only was not necessary for learning. Instead, participants can combine constraints from language and environment to support acquisition.