Redundancy and Complementarity in Language and the Environment: How Intermodal Information is Combined to Constrain Learning

To acquire language, learners have to map the language onto the environment, but languages vary as to how much information they include to constrain how a 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. There were three conditions, involving different language variants. All variants had free word order but varied as to whether or not they contained morphosyntactic information that defined 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 variant, demonstrating that learners are not reliant on information within a language only, but can combine constraints from language and environment to support acquisition. Data and analyses are available at: A one-page Accessible Summary of this article in nontechnical language is freely available in the Supporting Information online and at