I investigate the issue of the context-dependence of counterfactual conditionals and how the context constrains similarity in selecting the right set of worlds necessary to arrive at the correct truth-conditions. I propose that similarity is constrained by what I call Consistency and Non-Triviality. Assuming a model of the discourse along the lines proposed by Roberts (2012) and Büring (2003), according to which conversational moves are answers to often implicit questions under discussion, the idea behind Non-Triviality is that a counterfactual statement answers a conditional question under discussion and, therefore, is required to make a non-trivial assertion. I show that non-accidental generalizations which have often been taken to play an important role in the interpretation of counterfactuals, are crucial in selecting which conditional question is under discussion, and I propose a formal mechanism to identify the relevant question under discussion.