Figure 8: Overregularizations of the -t participle suffix. Longitudinal data covering the age period from 1;10 to 3;9 divided into 14 corpora. Overregularization rates for -t were calculated against the total number of correctly inflected irregular participles. From 2;1 onwards there is a relatively constant overregularization rate of 5% to 10% compared to 90% to 95% correctly inflected participles of irregular verbs. This is preceded by a stage without any -t overregularizations.