This article discusses cases of phonological abstractness and opacity and shows how they are eminently learnable, given certain assumptions about the innate cognitive endowment that learners bring to acquisition. I argue that opacity is not a learning problem but its solution. I propose that a distinction in patterning between two types of i in Inuit dialects is best explained by positing that surface [i] represents a merger of two underlying vowels. The apparently similar case of /i/ in Uyghur is shown to require a different type of solution. A review of contrasting approaches to prefix selection in Esimbi shows that opacity plays no role in evaluating their relative learnability. Though a celebrated case of opacity in Polish appears to have been misanalysed, an abstract analysis can still be motivated to account for alternations in certain lexemes. Uniting these cases is a preference for phonological analyses over diacritics or suppletion.
