The originator of the comprehensible output hypothesis, Merrill Swain (Swain, 1985), does not claim that CO is responsible for all or even most of our language competence. Rather, the claim is that "sometimes, under some conditions, output facilitates second language learning in ways that are different form, or enhance, those of input" (Swain and Lapkin, 1995, p. 371). A look at the data, howev...