This paper explores how five key complementary features of variable systems—overall rates, variant conditioning, productivity, contextual dispersion, and diffusion in the community—must be marshaled to provide a more comprehensive characterization of change in progress. We illustrate by revisiting a robustly variable sector of Canadian French morphosyntax whose variants are known to be in flux: the polar interrogative domain. Analyses extend the timeline of Elsig (2009)/Elsig and Poplack’s (2006) diachronic analysis by an additional twenty-five years, bringing 2,000+ questions produced by 133 speakers to bear on developments occurring over a period of nearly a century and a half of spontaneous Québec French speech. Results underscore the need to consider more than rates and conditioning in the study of language change. Linguistic dispersion and diffusion in the community provide crucial insight into the mechanics of the transition period and contribute to identifying shifts in variant productivity at each point in time.

Phonological rule innovation is thought to come about via reanalysis of some phonetic variation (e.g., Bermúdez-Otero, 2007; Hyman, 1975; Ohala, 1981; Pierrehumbert, 2001). Yet, empirical evidence suggests instead that the role of phonetic variation during phonological rule innovation is minor (Fruehwald, 2013, 2016). This paper adds to this ongoing debate an empirical analysis of an emergent allophonic contrast—an “/æ/ nasal system”—in White Michigan English. Analyses of speaker-level acoustic data from a sociolinguistic corpus (n = 36) and a subphonemic judgment task (n = 107) suggest that Lansing exhibits gradual phonological rule emergence. Social conditioning appears to act as the catalyst of phonological rule formation and its spread. The mechanism of actuation was thus “the chance alignment of social and phonetic variability” (Baker, Archangeli, & Mielke, 2011), suggesting that social conditioning on phonetic variability must play a major role in phonological emergence.

Subject dislocation (SD) is common across languages. In French, it is a vernacular norm. In English, it is comparatively rare. This article examines English SD in a unique contrastive situation in Ontario, Canada: two communities where SD is a community norm, one where individuals speak both English and French (Kapuskasing), and the other where the population speaks English only (Parry Sound). Dislocated subjects are produced by the same underlying linguistic mechanisms in both places, with parallel constraints by type of subject and intervening material, suggesting a typological universal. However, SD is age-graded in Kapuskasing, regardless of heritage language. In Parry Sound, it is obsolescent, in steady decline over the twentieth century. We conclude that while typological trends are underlain by universal cognitive processes, locally embedded sociocultural influences are the source of differentiation.

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.

Shifts in the frequencies of English modals of obligation have been linked to shifts in modal function and changing interpersonal authority. Interpretation of over 2,000 tokens in spontaneous speech data recorded in Sydney, Australia, in the 1970s and 2010s establishes a replicable classification of obligation meanings, based on source of obligation, with a three-way distinction between Hierarchical authority, General circumstances, and Personal choice. Competing expressions for these obligation types, besides have to, have got to, and older must, include should and, recently, need to. Two sets of regression analyses provide evidence of covariation of form and function: first, the linguistic and social conditioning of forms, with meaning as one of the predictors; and second, the conditioning of function, with modal form as a predictor. Need to rises in real time and so does talk of personal obligation. However, the change in modal function is concomitant with, but independent of, shifting modal forms.