Syntactic islands offer a window into core properties of language, and understanding cross-linguistic variation in islands is central to elucidating these properties. One language claimed not to instantiate several common wh-island restrictions is Spanish; yet recent experimental work has raised doubts about these claims. We address methodological and empirical gaps in the literature on cross-linguistic variation of island effects with an acceptability judgment experiment designed to provide a comprehensive view of wh-islands in Spanish. We observe large island effects for extraction over wh-adjuncts (like por qué ‘why’) and wh-arguments (like quién ‘who’), and smaller effects for extraction over whether (si). Moving beyond the group-level effects, we carefully examine score distributions and the role of individual variation in sentence judgments to conclude wh-arguments and wh-adjuncts show distributions consistent with islandhood, while apparent effects for si ‘whether’ islands may have an extra-grammatical source. Thus, Spanish in fact exhibits island effects, contra previous claims, yet also differs from some other languages in permitting extraction in some cases. Accounting for this variation is crucial for linguistic theory, and our results present challenges to major theoretical approaches to islands. Furthermore, with the increasingly central role of experimental methods to syntactic theory, our work’s careful consideration of methods and analysis contributes to a necessary discussion about the scope of interpretation in experimental syntax.

Some languages have a fixed subject position, while others are more flexible. Languages like English require pre-verbal subjects; languages like Spanish allow subjects in postverbal position. Because this difference clusters with several linguistic properties distinguishing the two languages, subjects in Spanish and English have been a perennial issue in linguistic theory, touching central problems like the EPP, the nature of cross-linguistic variation, and the relationship between core functional heads. Our project contributes a novel source of evidence to these debates: Spanish/English code-switching. Code-switching, the use of two languages in one utterance, combines the languages’ lexical items and their attendant syntactic features in a single derivation. Because code-switching, like all natural language, is rule-governed, researchers can exploit judgments about the well-formedness of code-switched sentences to draw conclusions about the combinations of features they represent. We report on a formal judgment experiment testing subject position in Spanish/English code-switching as a function of the presence of two functional heads known (from monolingual evidence) to affect subject placement: the C(omplementizer) and T(ense) heads. By manipulating which head appears in which language, we test the availability of post-verbal subjects under different feature combinations. Our results show that post-verbal subjects are only available when both C and T are in Spanish; neither Spanish head alone is sufficient. This finding suggests that the features regulating subject position stem from neither head alone, which is problematic for traditional approaches to the EPP as a feature of T but in line with other recent research on null subjects.

The that-trace effect is the fact that many languages (like English) ban the extraction of embedded-clause subjects but not objects over an overt complementizer like that, while many other languages (like Spanish) allow such extractions. The effect and its cross-linguistic variation have been the subject of intense research but remain largely a mystery, with no clear consensus on their underpinnings. We contribute novel evidence to these debates by using Spanish–English code-switching (the use of two languages in one sentence) to test five contemporary theoretical accounts of the that-trace effect. We conducted a formal acceptability judgment experiment, manipulating the extracted argument and code-switch site to test different combinations of linguistic features. We found that subject extraction is only permitted in Spanish–English code-switching when both the C head (que ‘that’) and the T head (i.e., the verb) are in Spanish, but not when either functional head is in English. Our results demonstrate indirect support for two of the five theories we test, failing to support the other three. Our findings also provide new evidence in favor of the view that the that-trace effect is tightly linked to the availability of post-verbal subjects. Finally, we outline how our results can narrow the range of possible theoretical accounts, demonstrating how code-switching data can contribute to core questions in linguistic theory.

Among methodological concerns specific to code-switching (CS) research is the design of the target stimuli used in experiments with an acceptability judgment task. We argue here that research which makes use of CS data of this type must also incorporate monolingual stimuli into the experimental design, specifically monolingual stimuli judged by the same bilingual participants who judge the code-switched stimuli. We do so by reviewing two sets of experimental CS data we collected and exploring the role that monolingual stimuli can play in the analysis of that data. In each experiment, an analysis based solely on acceptability judgments of the CS stimuli leads to one interpretation, while incorporation of results from the monolingual stimuli leads to a distinct interpretation. We show that it is the interpretation integrating the monolingual acceptability judgments which is more valid, thereby arguing for the value of monolingual stimuli in design and analysis.

Many languages, including English, exhibit a restriction on subject extraction over complementizers called the that-trace effect. Although extensively studied, this phenomenon remains a puzzle. Not all languages exhibit the effect; Spanish does not. Spanish also allows postverbal subjects, while English does not, which has been linked to the that-trace effect. Because Spanish/English differ in these properties, combining lexical items from both languages in a single derivation, as in code-switching, offers additional insight into the nature of the restriction. Two acceptability judgment tasks of Spanish/English code-switching reveal that a single Spanish functional head is insufficient to license either postverbal subjects or subject extraction. Instead, we argue, the that-trace effect and related properties arise from the interaction of two heads.

Abstract Using predictions from the Interface Hypothesis and the grammar of Spanish-English bilinguals, we test whether non-syntactic factors play a role in the that-trace effect. Though generally analyzed syntactically, some work on that-trace supports a syntax-prosody account (Kandybowicz, 2006). The Interface Hypothesis predicts that bilinguals will have difficulty with interface phenomena but not narrow syntax, such that testing bilinguals’ knowledge of that-trace provides a unique testing ground for comparing the two approaches. We demonstrate that bilinguals have the syntactic underpinnings necessary for both syntactic and syntax-prosody accounts of that-trace; however, they differ from the monolinguals with regard to that-trace, extending the phenomenon’s restriction on extraction to a new context, supporting a syntax-prosody account of that-trace.

Various methodological concerns are specific to code-switching research; however, the modality of experimental stimuli has yet to be thoroughly investigated. This study explicitly tests if the mode of presentation does in fact affect participants' judgments in Spanish-English code-switching using two different syntactic phenomena: (i) pronouns and lexical DPs, and (ii) wh-movement. The results are parallel, but not identical for the two modalities. We found no difference on a global level, indicating that written code-switched stimuli do not produce depressed ratings. We found a few individual differences when looking at specific structures within the two phenomena. In those cases, the aural condition enhanced the ratings of more acceptable sentences. Crucially, these differences did not affect the interpretation of the results.

This dissertation draws on the systematic nature of restrictions on code-switching (CS) to provide evidence concerning the morphosyntactic properties of wh-questions in Spanish and English, particularly with respect to inversion. CS allows one to independently control the language of individual words, and their associated syntactic properties, and observe the effect that those properties have on a given sentence's acceptability. In this way, CS becomes a tool of linguistic analysis. Data comes from Spanish-English CS. Both Spanish and English exhibit a phenomenon known as subject-version, in which the subject is sometimes required to appear after the verb or auxiliary, but the structural requirements vary by language and include various factors. This raises two important questions that are the focus of this dissertation: (i) what head or phrase ultimately determines the word order (i.e. the grammatical subject positions) in a given wh-question? and (ii) what are the restrictions on code-switching between the complementizer head, the tense head, and the wh-phrase? To answer these questions, a controlled experiment was conducted in which participants provided written acceptability judgments for both CS and equivalent monolingual sentences. In response to the first question, the results of this dissertation provide evidence that the complementizer is ultimately responsible for determining the properties of inversion for a given wh-question. Regarding the second question, the results also provides evidence for restrictions on code-switching between C and T and C and the wh-phrase. In particular, it provides evidence that a code-switch between an English simple wh-phrase and a Spanish C is ungrammatical in embedded questions with a Spanish T. Additionally, this dissertation serves as one example of an experimental approach to investigating code-switching, particularly with respect to syntactic structure. There are a variety of different concerns that need to be addressed in conducting such research, and this dissertation offers one perspective. In conclusion, the combination of controlled experimental methods and the unique analytical potential of CS to tease apart otherwise opaque syntactic relationships makes for a valuable tool for addressing a wide range of questions in theoretical linguistics.

Abstract This article addresses methodological concerns in research on grammatical aspects of code-switching. Data from code-switching have the potential for a unique contribution to linguistics by giving us access to combinations of linguistic features that may be difficult (or impossible) to observe in monolingual data. Nonetheless, the use of code-switching data for linguistic inquiry is not without issues. In this paper, we focus on three methodological questions specific to code-switching research: (i) project design, (ii) experimental procedure and (iii) participant selection. Drawing on experimental data from both published works and in-progress projects, we highlight potential solutions to each methodological challenge, concluding that several solutions are often required to mitigate the impact of confounding variables. In line with previous work (e.g. Grosjean 1998, Gullberg, Indefrey & Muysken 2009), we suggest that researchers clearly report on their methodology. Our overall goal is to contribute to a dialogue on best practices in code-switching research.

There are two particularly salient properties of wh-questions in both Spanish and English: fronting of the wh-phrase and inversion of either the subject and verb (Spanish) or the subject and auxiliary (English). In the case of inversion, this is not a unitary phenomenon, as evidenced by the matrix-embedded asymmetry of English and the argument-adjunct asymmetry of Spanish, and the ultimate motivation for the inversion is not clear. The question is why it is possible in those contexts and not in any others. For example, what makes the process of inversion in Spanish sensitive to the thematic status of the wh-phrase? In fact, this sensitivity can offer clues about how inversion proceeds in the two languages. In this presentation, I review several other types of sensitivity beyond those of the previously mentioned asymmetries and explore their implications for the underlying mechanisms behind the phenomenon of inversion using evidence from Spanish-English code-switching.

The aims of the present study were twofold. The study addressed the issues of simultaneous attention to form and meaning in second language (L2) written input and reactivity of think-alouds. Specifically, the study examined the comprehension of L2 learners of Spanish who either attended to lexical or grammatical forms while reading for meaning or read for meaning alone. Learners completed these tasks while either thinking aloud or not. Results indicated only a minimal effect for thinking aloud that did not appear to compromise the internal validity of the study. Additionally, results showed that attending to grammatical or lexical form while reading for meaning did not affect comprehension. Indeed, learners who processed these forms more deeply evidenced greater comprehension. These findings are considered in light of methodological issues and the larger issue of simultaneous attention to form and meaning in a L2.