Testing alternative theoretical accounts of code

Spanish and English contrast in adjective–noun word order: for example, brown dress (English) vs. vestido marrón (‘dress brown’, Spanish). According to the Matrix Language model ( MLF) word order in code-switched sentences must be compatible with the word order of the matrix language, but working within the minimalist program (MP), Cantone and MacSwan arrived at the descriptive generalization that the position of the noun phrase relative to the adjective is determined by the adjective’s language. Our aim is to evaluate the predictions derived from these two models regarding adjective–noun order in Spanish–English code-switched sentences. We contrasted the predictions from both models regarding the acceptability of code-switched sentences with different adjective–noun orders that were compatible with the MP, the MLF, both, or none. Acceptability was assessed in Experiment 1 with a 5-point Likert and in Experiment 2 with a 2-Alternative Forced Choice (2AFC) task. Data from both experiments were subjected to linear mixed model analyses. Results from the 2AFC task were also analyzed using Thurstone’s law of comparative judgment. We found an additive effect in which both the language of the verb and the language of the adjective determine word order. Both experiments examine adjective–noun word order in English–Spanish code-switched sentences. Experiment 2 represents a novel application of Thurstone’s law of comparative judgements to the study of linguistic acceptability which yielded clearer results than Likert scales. We found convincing evidence that neither the MLF nor the MP can fully account for the acceptability of adjective–noun switches. We suggest that advances in our understanding of grammaticality in code-switching will be achieved by combining the insights of the two frameworks instead of considering them in isolation, or by espousing a probabilistic model of code-switching