Abstract This chapter reports on two turn-initial particles in Spanish: bueno and pues. While previous research has equated both of these to well-prefacing in English in that they project “unexpectedness”, here the aim is to explicate the distinct interactional work that each particle performs. Focusing on responses to questions, I show that bueno-prefaced responses do not overtly problematize the prior utterance, but rather accept its terms before departing from them, and thereby acquiesce to the prior turn’s design. Pues-prefaced responses, by contrast, are directly addressed to the prior turn, but they cast that prior turn’s action or design as problematic in some way. I conclude by illustrating how these two uses are not mutually exclusive by examining the compound preface bueno-pues.