LingWorlds js a computer-based research system for teaching beginning aural comprehension skills for second (natural) languages. The results of this research include: 1) LingWorlds, a microworld environment and construction-based authoring system for second-language tutoring which permits students to engage in listening oriented communicative interactions with simulations of real world problems; and 2) new insight into the nature of language learning and teaching gained by computational modeling of tutoring and learning based on a specific pedagogical theory. Both of these have impact on second-language instruction and on the design of other instructional software systems.