[LAB] The hypothesis that “invited inferences” are factors in change and challenges to it are reviewed. In light of recent work on historical construction grammar and interactional discourse analysis, I suggest that at least three types of inferences play a role in interactional contexts: local inferences associated with specific expressions; discourse structuring inferences pertaining to factors like coherence, backgrounding and foregrounding; and turn-taking inferences associated with turn relevant positions. A case study tests this suggestion: the development of discourse structuring uses of a family of Look expressions. Turn-taking has been regarded as a trigger in related changes. However, in this case not turn-taking, but rather a profile shift associated with non-use of complementizers is hypothesized to be a crucial enabling factor.