This monograph deals with the locative alternation in German, a change in the argument structure of verbs like spray and load. Like most argument structure changes, the alternation is both productive and constrained: new forms may be derived, but not from all candidate verbs. This raises a learnability problem: how can children determine, in the absence of negative evidence, which verbs participate in the alternation? This book tries to answer this question by providing an in-depth analysis of the conditions that verbs must meet in order to participate in the alternation.