Modeling diachronic change in the third person singular: a multifactorial, verb- and author-specific exploratory approach

This study addresses the development of the English third-person singular present tense suffix from an interdental fricative (giveth) to an alveolar fricative (gives). Based on the PCEEC corpus, we analyze more than 20,000 examples from the time between 1417 and 1681 to determine (i) the temporal stages in which this development took place and (ii) the factors that are correlated with this change. As for (i), we use a bottom-up clustering method which shows that the shift from -(e)th to -(e)s is best characterized as consisting of five stages. As for (ii), we examine multiple language-internal and language-external factors, including several variables proposed in earlier accounts. We fit a generalized linear mixed-effects model, which allows us to predict nearly 95 per cent of all inflectional choices correctly, thus revealing which factors shaped the development over time in a data-driven and highly precise way.