A common practice often attested in bilingual and multilingual communities the world over is the combination of languages within a single utterance or conversation, a practice known as codeswitching. While sociolinguistic studies of spontaneous codeswitching have demonstrated its structure and systematicity, psycholinguistic approaches have focused on the cognitive mechanisms underlying language switching, most often at the lexical level. In the present study, we seek to investigate these mechanisms using spontaneous codeswitching from an established community of Spanish-English bilinguals in northern New Mexico. Focusing on the clausal rather than the lexical level, we find that global speech rates are fastest when bilinguals codeswitch compared to speaking only one language at a time. These results point to codeswitching as a unique discourse mode that these bilinguals use to facilitate production and suggests that what may appear costly at one level may be beneficial at another.

In English-Spanish code-switching, the main and complement clause boundary is a site of variable equivalence between languages. Whereas the complementiser is always present in Spanish, in English it is only sometimes present, giving rise to a quantitative word string mismatch at this juncture. Comparisons with monolingual benchmarks reveal no grammatical convergence of the contact varieties in finite complementation patterns. Rather, prosody provides a solution to variable equivalence. Whereas main and complement clauses tend to be prosodically integrated by occurring in the same Intonation Unit in unilingual speech, the opposite is true when there is code-switching at the clause boundary. Prosodic distancing of the two languages at junctures of variable equivalence is thus a bilingual strategy for code-switching between separate grammars.

Building on studies seeking to position the Romance languages on the cline of grammaticalization, this study targets the evolution of subjunctive into subordination marker in speech corpora of French, Italian, Portuguese and Spanish. By considering the conditioning of variation between subjunctive and indicative in complement clauses, we operationalize parameters of late-stage grammaticalization, and establish measures of productivity. Results show that, with the exception of Spanish, subjunctive selection is constrained neither by contextual elements consistent with its oft-ascribed meanings nor by semantic classes of governors harmonic with such meanings. Instead, in all four languages, lexical bias is the major predictor of subjunctive selection, abetted by structural elements of the linguistic context. The overriding processes are lexical routinization, which is language-particular, with cognate governors displaying idiosyncratic associations with the subjunctive, and structural conventionalization, which is cross-linguistically parallel, with languages differing merely in degree.

This variationist study examines finite clausal complementation with respect to the prosodic integration of matrix clauses (MC) and complement clauses (CC). In both Spanish and English conversational data, MCs and CCs are found to occur in a single prosodic unit, or Intonation Unit (IU), over two-thirds of the time. The presence of syntactic material (e.g., adverbs) intervening between MC verb and CC (and complementizer that, in English) favors CC occurrence in a different IU. A contrary effect, favoring CC occurrence on the same IU, is that of first person MC subjects, which may form part of formulaic expressions. These discourse-cognitive constraints provide cross-linguistic evidence for the interaction of syntax with prosody in speech.