 Hello, this unit investigates how words are stored in the mental lexicon. From a theoretical point of view, there are two extremes, a root lexicon and a full form lexicon. However, since morphological processes involve different degrees of productivity, which in turn influence the structure of the lexicon, we may also propose alternatives in this unit. In the virtual session, we will first look at morphological productivity, that is, we will find out whether a morphological rule or pattern can be applied to new bases in order to form new words or not. The result of this discussion has some interesting consequences for the structure of the lexicon, which constitutes the focus of the second part of the virtual session. Use the question sheet with its video links and hyperlinks as default guidance if you don't know where to start. The mastery worksheet is a dynamic multiple-choice test with several questions about the mental lexicon and the practical wants you to set up lexical entries and look at productivity issues from various morphological perspectives. Not easy, but certainly manageable.