“…Epistemic main subjects (first-and secondperson pronouns) and verbs (like think and guess), which are often used to express speakers' epistemic claims or degree of speaker's commitment, are more likely to be grammaticalized into epistemic phrases or discourse formulas, and hence should correlate with a lower rate of that-use (Thompson & Mulac, 1991b). However, this hypothesis seems to be contradictory to recent diachronic findings, where many frequent mental verbs, such as think, suppose, know, believe, and understand undergo an overall increase in use of that from the sixteenth to twenty-first centuries (Shank & Plevoets, 2018).…”