This article is a conceptual and methodological exploration of a new construct, task interactional difficulty, and of a possible approach to assessing task demands in general. After arguing for the use of 'task difficulty' instead of 'task complexity', the notion of task interactional difficulty is analyzed, first by reviewing previous SLA…

Languages spoken in larger populations are relatively simple. A possible explanation for this is that languages with a greater number of speakers tend to also be those with higher proportions of non-native speakers, who may simplify language during learning. We assess this explanation for the negative correlation between population size and…