This research investigates children's knowledge of how surface pronunciations of lexical items vary according to their phonological and morphological context. Dutch-learning children aged 2.5 and 3.5 years were tested on voicing neutralization and morphophonological alternations. For instance, voicing does not alternate between the pair [p[epsilon]t]~[p[epsilon]t[schwa]n] (cap~caps) but does in [b[epsilon]t]~[b[epsilon]d[schwa]n] (bed~beds). Data from the first experiment showed that children at a younger age were less accurate at imitating words with /d/ than /t/, regardless of morphological context. In a second study, children between 2 and 4 years were asked to produce singulars from novel plurals (e.g., [k[epsilon]t[schwa]n]~[k[epsilon]t] and [k[epsilon]d[schwa]n]~[k[epsilon]t]). Results indicated that children's performance was better in contexts that did not require surface variation. Dutch-learning children are not able to robustly generalize their knowledge of phonotactics and morphophonological alternations. Rather, it appears that their knowledge is more concrete, in line with recent usage-based theories of acquisition.