MacWhinney's list of proposed mechanisms for language acquisition seems so all-encompassing that it might appear churlish to dwell on a mechanism that's left out, but on his ultimate list of critical mechanisms there is an indeed an important (and intended) omission: innate, linguistically-specialized constraints. Such constraints are indeed mentioned, but if I understand the point of the article correctly, it is to argue that seven cognitive mechanisms, ranging from competition to cue construction, indirect negative evidence and monitoring, collectively obviate the need for any innate machinery that it specialized for language. Why not include room for innate, domain-specific constraints, too?