We use a mathematical model to examine three phenomena involving language change across the lifespan: the apparent time construct, the adolescent peak, and two different patterns of individual change. The apparent time construct is attributed to a decline in flexibility toward language change over one's lifetime; this explanation is borne out in our model. The adolescent peak has been explained by social networks: children interact more with caregivers a generation older until later childhood and adolescence. We find that the peak also occurs with many other network structures, so the peak is not specifically due to caregiver interaction. The two patterns of individual change are one in which most individuals change gradually, following the mean of community change, and another in which most individuals have more categorical behavior and change rapidly if they change at all. Our model suggests that they represent different balances between the differential weighting of competing variants and degree of accommodation to other speakers.

Word production variability is widespread in speech, and rates of variant production correlate with many factors. Recent research suggests mental representation of both canonical word forms and distinct reduced variants, and that production and processing are sensitive to variant frequency. What factors lead to frequency-weighted variant representations? An experiment manipulated following context and word repetition for final t/d words in read, narrative English speech. Modeling the experimentally generated data statistically showed higher final-segment deletion in tokens followed by consonant-initial words, but no evidence of increased deletion with repetition, regardless of context. Deletion rates were also higher the greater a word's cumulative exposure to consonant contexts (measured from distributional statistics), but there was no effect of word frequency. Token effects are interpreted in terms of articulation processes. The type-level context effect is interpreted within exemplar and usage-based models of language to suggest that experiences with word variants in contexts register as frequency-weighted representations.

The present study analyzes present be leveling with pivot is (as in I is, we is, the old dogs is) in Tristan da Cunha English, a variety of South Atlantic English that developed in geographic isolation and under intense contact conditions. The findings, based on data from a total of 45 speakers born throughout the 20th century, indicate that community-wide variation correlates with social history; whereas present be was subject to (near-)categorical leveling until the 1940s, an opening-up phase after World War II saw interaction with speakers of other dialects on the island, which triggered an increase of a standard am/is/are concord pattern. Variability began to increase from the 1950s onward and the community has now frayed out widely in its usage of leveled is forms (ranging from 10% to over 90% in speakers of the youngest generation, born in the 1980s). The internal constraint ranking for preceding environment in younger generations was partially restructured, which suggests that the social changes affected the grammatical variable. Three outliers represent exonormative orientation and outward mobility.

Previous studies of language contact in multilingual urban neighborhoods in Europe claim the emergence of new varieties spoken by immigrant-background youth. This paper examines the sociolinguistic conditioning of variation in allophones of Swedish /ε:/ of young people of immigrant and nonimmigrant background in Stockholm and Gothenburg. Although speaker background and sex condition the variation, their effects differ in each city. In Stockholm there are no significant social differences and the allophonic difference appears to have been neutralized. Gothenburg speakers are divided into three groups, based on speaker origin and sex, each of which orients toward different norms. Our conclusions appeal to dialectal diffusion and the desire to mark ethnic identity in a diverse sociolinguistic context. These results demonstrate that not only language contact but also dialect change should be considered together when investigating language variation in modern-day cities.

Korean has a typologically unusual three-way laryngeal contrast in voiceless stops among aspirated, lenis, and fortis stops. Seoul Korean is undergoing a female-led sound change in which aspirated stops and lenis stops are merging in voice onset time (VOT) and are better distinguished by the F0 (fundamental frequency) of the following vowel than by their VOT, in younger speakers' speech. This paper compares the VOT pattern of Homeland (Seoul) and Heritage (Toronto) Korean speakers and finds that the same change is in progress in both. However, in the heritage variety, younger speakers do not advance the change, unlike their Seoul counterparts. Rather they have leveled off or are perhaps reversing the change, and there is very little sex difference among the younger heritage speakers' patterns. We consider possible accounts of the differences between the Seoul and Toronto patterns, building our understanding of how language-internal variation operates in bilingual speakers, a topic that has received relatively less attention in the variationist literature.