The main ongoing debate within the recently-established field of Third Language (L3) Acquisition revolves around which of the previously-acquired languages prevails as a source of cross-linguistic influence (CLI) during production in the target language. Whereas several factors have been found to promote CLI, the existing body of L3 research points to a potential stronger rivalry between two of them: typology, or the relative distance among the languages involved, and second language (L2) status, also known as foreign language effect. In fact, they are at the core of two models of multilingual transfer that stem from the area of L3 morphosyntax, namely the Typology Primacy Model (TPM; Rothman, 2010, 2011, 2013, 2015), and the L2 Status Factor Model (L2 SFM; Bardel & Falk, 2007, 2012). For the most part, claims backing a more determinant role for typology come from studies investigating lexis. Whether or not typology overrides the effect of the L2 with regards to syntax and phonology as well is less clear. On the one hand, studies focusing on syntactic CLI can be divided into those whose findings suggest a crucial role either for the L1 (Na Raong & Leung, 2009) or for the L2 (Bardel & Falk, 2007), those in which findings point to typology as the deciding factor in determining a source of CLI (Rothman, 2011), and those that fail to show any influence from the L2 on the L3 (Håkansson, Pienemann, & Sayehli, 2002) even when the L2 and the L3 are typologically close (Martínez Adrián, 2005). On the other hand, results from previous research investigating phonological CLI also yield three main distinct findings: i) a more marked L2 effect (Llama, Cardoso & Collins, 2010), ii) a predominant influence from the first language (L1; Llisterri & Poch, 1987), and iii) combined CLI, that is, the L1 and the L2 concur in influencing the L3 (Wrembel, 2014). The primary goal of this dissertation is to add to the debate by looking into all three sub-areas among trilinguals at a high-intermediate to advanced level of proficiency, which has been the least targeted proficiency level until now. The selected topics, per area, are: lexical inventions, relative clause attachment preferences (RCA), and voice onset time (VOT). The secondary goal was to compare the relative influences of typology and L2 status across sub-areas, and to examine all results in light of three of the current L3 multilingual transfer models, the TPM, the L2 SFM, and the Cumulative Enhancement Model (CEM; Flynn, Foley, & Vinnitskaya, 2004). The results obtained are in clear agreement with previous reports in the area of lexis. However, the interplay of our trilinguals’ linguistic systems with regard to RCA and VOT is more complex. Findings in these areas seem to suggest that other factors (language exposure in the case of RCA, and the L1, in the case of VOT) may trump the two under investigation.

Varios estudios han demostrado convincentemente que no solamente la L1, sino también la L2 puede afectar la adquisición de la L3. En particular, la L2 puede transferirse a la L3 si los dos idiomas tienen en común la estructura gramatical (Flynnet al., 2004) o la estructura sintáctica (Bardel y Falk, 2007). Asimismo la L2 puede afectarel aprendizaje de la L3 en el estado inicial de adquisición (Rothman, 2011). En este estudio, investigamos más a fondo las transferencias lingüísticas de L1/L2 a L3 en un grupo de estudiantes suecos en la etapa superior de la Educación Secundaria Obligatoria sueca que ya hablan inglés como L2 y que están aprendiendo la lengua meta. También investigamos la percepción de un grupo de profesores de español en Suecia sobre las transferencias a la lengua meta. Los datos se han obtenido de 41 pruebas de escritura de estudiantes suecos de español y de unas entrevistas a 6 profesores de español en Suecia. Los resultados de nuestro estudio muestran que las transferencias lingüísticas son una muestra del progreso en el aprendizaje de la lengua meta y pueden ocurrir tanto desde L1 como desde L2, aunque las transferencias que ocurren desde el idioma más cercano a L3 pueden facilitar la comunicación. Además se concluye que esmás frecuente que las transferencias disminuyan cuando aumentan las habilidades en L3. / Several studies have convincingly shown that not only the L1, but even the L2 may affect the L3 acquisition. The L2 may especially transfer to the L3 if the two languages have in common the grammatical structure (Flynn et al., 2004) or the syntactical structure (Bardel and Falk, 2007). In particular, the L2 may affect the acquisition of the L3 at the initial state (Rothman, 2011). In this study we further investigate linguistic transfers from L1/L2 to L3 in Swedish learners in the upper stage of the Swedish lower secondary education who already speak English as L2 and who are learning the target language. We also investigate the perception of a group of Spanish teachers in Sweden about the transfer to the target language. Data have been obtained from 41 writing tests by Swedish learners of Spanish and from interviews to 6 Spanish teachers in Sweden.The results of the study show that linguistic transfer is a sign of learning progress in the target language and can occur from both L1 and L2, although transfers that occur from the language closest to L3 can facilitate the communication. Furthermore, it is concluded that it is more frequent that transfers decrease when skills in L3 increase.

Notre recherche s’inscrit à la fois dans le domaine des Recherches sur l’acquisition des langues et celui de la Didactique des langues étrangères, et poursuit un double objectif. D’abord, nous avons décrit les influences translinguistiques, issues de l’espagnol L1 comme de l’anglais L2, dans le processus d’acquisition de certaines structures liées au groupe verbal en français L3, à savoir la construction des verbes avec des compléments nominaux, la sélection des prépositions introduisant éventuellement ces compléments et l’acquisition des pronoms compléments. Pour cela, nous avons pris en compte les apports théoriques des recherches sur l’acquisition plurilingue mais également des études ayant dégagé des itinéraires de développement pour le français. Nous nous sommes basée sur des productions écrites réalisées par des étudiants, débutants en français, de première année de la filière de Traduction/Interprétation de la Universidad de Concepción au Chili.Le deuxième objectif de notre recherche correspond à une démarche de transposition didactique de résultats empiriques dans le but de mieux accompagner l’apprentissage du français dans notre contexte de formation. Nos propositions didactiques concernent aussi bien la sélection et le séquençage des contenus grammaticaux, la démarche méthodologique d’enseignement de la grammaire, et la correction/évaluation de la compétence grammaticale des apprenants. In fine, notre objectif didactique est de contribuer à la formation d’apprenants plurilingues conscients des processus à l’œuvre dans leur acquisition, et de les accompagner dans un usage réflexif de leurs connaissances linguistiques, notamment grammaticales. / Our research is related both to Second Language Acquisition Research and to Foreign Language Didactics, and has a twofold objective.First, we described crosslinguistic influences, from Spanish L1 and English L2, in the acquisition processes of some structures related to the verb construction in French L3, i.e. the verb construction with noun phrases, the selection of prepositions that potentially introduce these complements, and the acquisition of complement pronouns. To carry out this identification of syntactic transfers, we consider theoretical contributions from both multilingual acquisition research and studies that define developmental stages in French acquisition. Our study is based on written productions taken from first-year students, beginners in French, of the Translation/Interpretation university program at Universidad de Concepción in Chile.The second objective of our research consists of a didactic transposition of empirical results in order to better support the learning of French in our training context. Our teaching proposals deal with the selection and sequencing of grammatical contents, the methodological approach of grammar instruction, and the correction/evaluation of learners’ grammatical competence. In the end, our didactic purpose is to contribute to multilingual learners training and self-conscience of their acquisition processes, to support them with the reflexive use of their linguistic knowledge, in particular their grammatical knowledge.