The distinction between arguments and adjuncts is fundamental to most linguistic theories, yet the distinction is not always clear. In addition to clear arguments and clear adjuncts, there are a number of unclear, in-between cases. These cases include passive agents, benefactives, directionals, and a number of other types of phrases. We argue that the in-between status of the unclear cases can be explained if they are analyzed as derived arguments; i.e., arguments that are added to verbs at the grammatical level of argument structure.