In this study, we present the first agent-based simulation of vowel chain shifts across large communities, providing a parsimonious reinterpretation of Labov's (2007) notions of transmission, diffusion, and incrementation. Labov determined that parent-to-child transmission faithfully reproduces structural patterns such as the Northern Cities Shift (NCS), but adult-to-adult diffusion does not. NCS is transmitted faithfully to new generations of U.S. Inland North children. But St. Louis speakers, depending only on adult-adult contact, only attain an incomplete, unsystematic version. Labov (2007) attributed the difference to children's superior language-learning ability; transmission and diffusion are categorically different processes in that approach. By contrast, our multiagent simulation suggests that such transmission/diffusion effects can be derived by simple density of interactions and simple exemplar learning; we also find that incrementation is a natural outcome of this model. Unlike Labov (2007), this model does not require a dichotomy between transmission and diffusion. While dichotomous assumptions about child versus adult learning may be necessary in other contexts, our results suggest that the NCS effects in Labov (2007) may be explained economically in terms of simple density of interactions between speakers. Our results also provide an agent-based perspective supporting and explicating the notion of speech community.

The possibility of referential null subjects in Old English has been the subject of conflicting assertions. Hulk and van Kemenade (1995:245) stated that “the phenomenon of referential pro-drop does not exist in Old English,” but van Gelderen (2000:137) claimed that “Old English has pro-drop.” This paper presents a systematic quantitative investigation of referential null subjects in Old English, drawing on the York-Toronto-Helsinki Parsed Corpus of Old English Prose (YCOE; Taylor, Warner, Pintzuk, & Beths, 2003) and the York-Helsinki Parsed Corpus of Old English Poetry (YCOEP; Pintzuk & Plug, 2001). The results indicate substantial variation between texts. In those texts that systematically exhibit null subjects, these are much rarer in subordinate clauses, with first- and second-person null subjects also being rare. I argue that the theory of identification of null subjects by rich verbal agreement is not sufficient to explain the Old English phenomenon, and instead I develop an account based on Holmberg's (2010) analysis of partial null subject languages.

This study examines the placement of an adverb with respect to a modal or perfect auxiliary in English (e.g., It might potentially escape / It potentially might escape). The data are drawn from two large, socially stratified corpora of vernacular English (Toronto, Canada, and York, England) and thus allow a cross-dialect perspective on linguistic and social correlates. Using quantitative sociolinguistic methods, I demonstrate similarity in the varieties, with the postauxiliary position generally strongly favored. Of particular importance is the structure of the auxiliary phrase; when a modal is followed by the perfect auxiliary (e.g., It might have escaped), the rates of preauxiliary adverb placement are considerably higher. As the variation is chiefly correlated with linguistic, rather than social factors, I apply recent proposals from Generative syntax to further understand the grammar of the phenomenon. However, the evidence suggests that the variability seen here is a result of postsyntactic, rather than syntactic, processes.

This study examines the internal and external constraints on glottal replacement of /t/ among adolescents in London and Edinburgh. Results show that phonological and stylistic constraints play an important role in determining the realizational variation of /t/, as many similar studies have shown. However, there is also clear evidence that our understanding of this phenomenon has been restricted by the limited set of factors that have been investigated previously, as results show that this feature is also constrained by word frequency and morphophonological factors. These findings raise important questions concerning the role of morphological compositionality in language change and the nature of lexical diffusion.

The emergence of être comme as a quotative verb in Canadian French is easily construed as a case of contact-induced change by virtue of its superficial similarity to the rapidly diffusing be like quotative (Tagliamonte & D'Arcy, 2007). We pursue the inference of contact-induced change by undertaking a quantitative analysis of French and English quotatives recorded from speakers in the bilingual city of Ottawa between 2008 and 2010. A series of real-time cross sections enables the longitudinal development of the quotative system of each language to be tracked. Analysis of the data confirms that être comme is a change in progress, but not a wholesale replication of its English counterpart. Although the results do not refute the role of external causation in the emergence of être comme, the available evidence suggests that an external source is neither the sole, nor even the preferred, motivation for the emergence of this innovation.