In this chapter I turn attention to the case of verb-forming word-formation processes in English. Here, I will offer an analysis of the affixes -ize and -ify which improves upon both my own previous research (Lieber 1998) and that of Ingo Plag (1999). In the course of this case study, I will continue to explore issues of affixal polysemy and the existence of multiple affixes with the same meaning. But I will also look in some depth at another productive source of new verbs in English, the process of conversion, and explore what the present theory has to say about the semantics of verbs derived without formal change from nouns. I will show in what follows that the range of polysemy exhibited by verbs formed by conversion in English cannot be explained as a result of the abstractness of skeletal material and variation in co-indexation, and indeed that conversion does not involve the addition of a single fixed skeleton, as derivation does. The semantic analysis of conversion that I will propose is consistent with, and lends support to, analyses of conversion that do not rely on so-called zero affixes, and therefore speaks to the third of the issues that I raised in the introduction to this work, namely the question of how we account for word formation in which there is semantic change with no concomitant formal change.