Word order and the learnability of artificial languages

Languages vary in the way they typically order subject, verb, and object in transitive sentences. Although all six possible word orders are attested, there is great variability in the frequency with which they occur in the languages of the world. Here, we investigate whether this variability is reflected in differences in the learnability of the possible word orders. Thus, we carried out a language learning experiment in which native English speakers had to learn artificial languages with different word orders. The results suggest that there is broad correspondence between the typological frequency of different word orders and their learnability, which supports the hypothesis that there are cognitive and/or communicative factors that are responsible for the bias in the distribution of word orders. We further analyse the data using a novel computational model for simultaneous vocabulary and word order acquisition.