The invisible hand of grammaticalization

Grammaticalization may have therapeutic and pathological effects on morphology. The paper will focus on these latter with special regard to the occurrence of a morpheme in an unexpected form as is the case for the West- Germanic substitutive infinitive. The reason for this mysterious case of formmeaning mismatch must be sought in the grammaticalization of the Germanic telic prefix *ga-. As a consequence of its grammaticalization in the past participle, a semantic incompatibility prevented the so-called AcI-verbs from being touched by the grammaticalization wave spreading the perfect periphrasis throughout the whole verbal system. Thus, the arguably default form came in, namely the infinitive, whereby the perfect periphrasis could be completely paradigmaticized even though at the cost of a form/meaning mismatch. In this light, the long-wave effect of grammaticalization can be made responsible for the anomaly preserved until today in all West-Germanic dialects, in which ge- was grammaticalized as an inflectional marker.