Age-grading—a cornerstone of sociolinguistic theorizing—is hypothesized to follow a U-shaped pattern. Vernacular forms peak in adolescence, abate in middle age, and increase again in retirement, forming a vernacular tail. A complete understanding of age-grading has been hampered by a lack of empirical evidence across the entire adult trajectory and a relatively narrow understanding of speakers’ motivations to change. This paper presents data from a dynamic panel dataset of Tyneside English speakers, covering successive cohorts over the entire adult lifespan. An analysis of (ing) reveals that the U-shaped curve is occupationally niched; only professional educators demonstrate clear retrenchment followed by a tail. Drawing on educational policy research, we argue this effect is largely driven by institutional (and heavily policed) expectations of UK educational policies. We are the first to demonstrate the occupationally niched nature of the U-shaped curve and provide quantitative evidence of the effect of educational policy on linguistic production.

We investigate the impact of medium of communication (in-person versus video) on intraspeaker variation in conversation—a process we refer to as medium-shifting. To quantify the effects of medium-shifting and understand its possible motivations, we analyze three variables that show intraspeaker effects of “clear” or “careful” speech: articulation rate, density-controlled vowel space area, and (ING). The data come from matched in-person and video-mediated interviews with thirty-three repeat guests from The Late Show with Stephen Colbert, recorded before and during the COVID-19 pandemic. Mixed-effects regression models show that compared to in-person interviews, video-mediated interviews involve a significantly lower articulation rate and larger vowel space, but no significant difference in (ING). The results suggest that speakers may engage in medium-shifting in order to enhance their intelligibility over video, for example, through more precise articulatory movements and greater contrast between phonemic vowel categories. The null effect of medium on (ING) further suggests that medium-shifting is a motivator of intraspeaker differences even within a single contextual style. An emergent extralinguistic factor affecting speaking behavior and choices, medium-shifting should be carefully considered especially when designing variationist research involving mixed media interviews.