This diachronic corpus of roughly 80 million word tokens contains large numbers of neologisms. Thus, this corpus offers a good opportunity to test both qualitative and quantitative theories of morphological productivity. Our investigations support the usefulness of the quantitative formalization of the notion Degree of Productivity developed in Baayen 1992, 1993a. At the same time, they illustrate that productivity is a function of both text type and real time. To replace the Grammatical infinitive hypothesis, we put forth the Modal hypothesis, which states that the distinction between finite and non finite forms can be accounted for by the modality of the sentence.
Nonfinite forms occur in modal contexts, and finite ones in nonmodal ones.