This study investigates the linguistic nature of code-switching (CS), the concurrent use of more than one language in bilingual conversational speech. Patterns of CS are not random but systematic, which suggests the possibility that CS is constrained by grammatical principles that underlie human language. This research will investigate CS across languages that have different canonical orders of object (O) and verb (V). CS data show that not only can a switch occur across languages with different canonical word orders, such as an OV language like Korean and a VO language like English, but the internal order of a code-switched constituent may also vary, exhibiting either order of the two languages involved in CS. This project tests the hypothesis that OV-VO variation in CS is due to properties of particular verbs but also the meaning of the resulting phrase after the verb has combined with an object. The project will test the predictions of such a theory against Korean-English and Japanese-English bilingual speakers' introspective judgments of CS patterns presented to them in the form of a questionnaire.
CS has been extensively studied, yet there has been no single satisfactory account to explain the diverse, yet systematic, word order patterns found in various language pairs. By offering a unified linguistic account of certain word order variations in CS, this research contributes to an understanding of variation in bilingual speech and how it is regulated. The results of the study will also bear on several current proposals in theoretical syntax. Applying these proposals to bilingual speech is an innovative way to evaluate them. Lastly, this study will have a broader impact on various social and educational aspects. CS is often stigmatized and work on CS will help reduce such negative perceptions. This study will promote CS as a legitimate language form of bilinguals, which is subject to the same universal principles that govern monolingual speech.
Under the assumption that parametric variation, such as word order, is determined by the absence or presence of certain features of a functional category as assumed in the Minimalist Program, the present research asked the fundamental question of how different functional categories in typologically different languages play a role to derive the various word orders in code-switching. More specifically, the role of light verbs was evaluated in comparison with that of heavy verbs in various code-switched phrases with respect to their contribution to O(bject)V(erb) and VO order variation in Korean-English and Japanese-English code-switching. In addition, the study also investigated whether the syntactic flexibility of a code-switched phrase, especially that of an idiomatic phrase, would be a factor in word order variation in code-switching, under the assumption that while the internal argument of the syntactically flexible phrase is subject to code-switching, the internal argument of the less flexible or inflexible phrase may not undergo code-switching, maintaining the internal order of the phrase throughout the derivation. The pattern of the results found in the code-switching judgment task and the syntactic flexibility judgment task from 28 Korean-English and 8 Japanese-English bilingual speakers confirmed the two research hypotheses that (i) the selection between English heavy verbs and light verbs within a code-switched constituent leads to OV~VO variation, and (ii) syntactically flexible and inflexible phrases also lead to OV~VO variation in code-switching. The intellectual merit of the study is twofold: First, in this study, the phenomenon of code-switching was accounted for via current linguistic theories and models, which have been proposed based on monolingual speech, yet claimed to be universal in all human languages. By applying these theories to the field of bilingualism, this study extends the application of current theoretical proposals and verifies the validity of various linguistic theories in a broader context. Secondly, this study investigates systematic grammatical patterns of code-switching and further explains linguistic constraints imposed on them. As a result, it informs various possible human language forms that are regulated under universal principles, which allows us to understand human language at a deeper level.
