This article investigates stem identity in the domain of irregular verbs for the morphological categories of the present tense, the simple past and the past participle. As past and participle both refer to past events, whereas the present tense does not, we assume the following: • The semantic distance between past and participle is smaller than the semantic distance between present and past or between present and participle. Our hypothesis is that semantic distance is reflected in formal distance. The formal distance between morphological categories is measured by counting the number of cases of stem identity in the set of irregular verbs for the present, the past and the participle. This yields the following prediction: • The number of paradigms with stem identity between past and participle of irregular verbs will be larger than the number of paradigms with stem identity between present and past or between present and participle. This prediction is tested on the basis of data from English, Frisian and Dutch.