Abstract This study provides an account of the puzzling difference in case marking of the object of two-argument verbs like aider (accusative) and obéir (dative) in French. Cross-linguistically, these two verb types usually mark their object identically (e.g., accusative in English, dative in German), but French historically shows divergent trajectories. Employing logistic regression modelling and clustering techniques, this corpus-based study examines 77 verbs over 1000 years of textual record to show that aider -type verbs and obéir -type verbs systematically diverge in their case selection by the 16th century and that they have been stable ever since. We argue that their trajectories reflect the narrowing of an oblique linking rule, defined in terms of Talmy’s theory of force dynamics, which targets the difference between helping and hindering verbs on the one hand and verbs of reacting and resisting on the other. The analysis dispels long-held views that the diachronic changes were random or based strictly on analogy, and methodologically, it provides an empirical basis for connecting historical change to developmental approaches to grammar.
Stein et al. (2026) studied this question.