Bilingual clause combining: A Variable Equivalence hypothesis for conjunction choice.

Bringing linguistic experience into code-switching (CS) constraints, a new hypothesis considers cross-language <italic>variable equivalence</italic>, which arises from within-language variability. Bilingual choices are assessed for Spanish-English CS between clauses, where subordinating conjunctions may not be consistently equivalent.Equivalence exists at the main-and-adverbial clause junction, inasmuch as the conjunctions are consistently present and placed the same way in the two languages. Equivalence is variable with main-and-complement clauses, because English complementizer <italic>that</italic> is mostly absent. Tokens of clause combining were extracted from the prosodically transcribed speech of members of a long-standing community in northern New Mexico who use both languages in their everyday interactions. Bilingual clause combinations were compared with their unilingual counterparts produced by the same speakers, as benchmarks.Over 2,000 tokens of clause combining were coded for conjunction, subordinate clause type, prosodic connection, and CS direction for bilingual instances (<italic>n</italic> = 189).Bilinguals treat CS with complement and adverbial clauses differently. With complement clauses, the rate of CS is lower, prosodic separation is greater and, most notably, conjunction language choice is more asymmetrical. Spanish complementizer <italic>que</italic> is overwhelmingly selected over English <italic>that</italic>. In contrast, choice between causal conjunctions <italic>porque</italic> and <italic>(be)cause</italic> is affected by CS direction.The Variable Equivalence hypothesis states that bilinguals favor CS with the equivalent option from one of the languages that is <italic>more frequent and predictable</italic> in their combined linguistic experience, considering both languages.CS constraints are probabilistic (preferred CS sites) rather than categorical (permissible CS sites). The Variable Equivalence hypothesis accommodates variation in actual language use. Methodologically, comparing spontaneous CS with the same speakers’ unilingual production allows discovery of CS asymmetries. These asymmetries reveal quantitative bilingual preferences to switch at particular sites. [ABSTRACT FROM AUTHOR]